 Lesson 4 of the Elements of Herpetology and Ectheology. This is a LibriVox recording. All LibriVox recordings are in the public domain. For more information or to volunteer, please visit LibriVox.org. Lesson 4. Order of Petrachia. Organization, classification, family of anora, metamorphosis of tadpoles, habits, frogs, tree frogs, toads, peepa, family of urodala, salamanders or water-nuts, family of brancifera, axolotl, minobronchus, proteus, siren, family of apoda, Cecilia. Order of Petrachians. The name Petrachian, from the Greek Petrakos, frog, is given to all reptiles that resemble frogs in their mode of organization. This fourth and last division of the class of reptiles brings us into the neighborhood of the fishes. For it is composed of the animals that, during the early period of their life, respire by branciae and resemble fishes in their habits and form as well as in their mode of organization, but which, with the advance of age, undergo a true metamorphosis and acquire characters common to other reptiles. When in this transitory state, they are called tadpoles. The branciae of young Petrachians are placed upon the sides of the neck and are sustained by the lateral prolongations of a cartilage which represents the hyoides. Sometimes they are in the form of external feathery tufts which float in the water. At others they consist of filaments fixed along the hyoid branches, just mentioned, and covered by the integuments. In proportion as the lungs become developed, in general, the branciae wither and, at last, entirely disappear. But this is not always the case, and in some reptiles they remain throughout life, conjointedly with the lungs. The apparatus of the circulation undergoes changes corresponding to those experienced by the organs of respiration. The heart of Petrachians, like that of most reptiles, is composed of two oracles and a single ventricle from which arises a great artery. At its base this artery is swelled into a contractile bulb and soon after bifurcates. When the animal breathes by branciae alone, the blood forced by the ventricle is distributed to these organs from which the greater part of it goes to the dorsal artery, the branches of which ramify in the various organs. In fishes this liquid follows the same course. But when the lungs are developed the disposition of the circulatory apparatus changes. There is established a direct communication between the vessels which carry the blood to the branciae and those that receive it from those organs so that it is not necessary for this liquid to pass through the respiratory apparatus to reach the dorsal artery and through it the different parts of the body. The artery which arises from the ventricle and which could be compared at first to a brancial artery then becomes the origin of the dorsal vessel and with it constitutes a true aorta. Certain branches of which that go to the lungs are developed at the same time and establish a pulmonary circulation. Finally the brancial vessels are obliterated and then the circulation is carried on nearly in the same manner as it is in other reptiles. The venous blood returning from all parts of the body is poured into the ventricle by one of the oracles and they are mixed with the arterial blood coming from the lungs and poured into the same ventricle by the other oracle. This mixture enters the aorta, a small portion goes to the lungs but the largest part is distributed to the different organs of the animal. The skeleton of protractions presents remarkable peculiarities. In general the ribs are entirely wanting or are merely rudimentary for which reason pulmonary respiration cannot be carried on by the ordinary mechanism and in fact the animal introduces air into its lungs by a species of deglutition. It is to be observed also that the skin of these reptiles is not covered with scales like those of Psaurians, Ophidians and most Chalonians but is naked. Almost all protractions are without nails. Their eggs are enveloped only in a gelatinous mass which swells very much in water and they are not generally fecundated until after they are laid. This order is divided into four families, namely first the enora which in their perfect state have no tail and do not preserve their branchier but are provided with four extremities. Second the urodella which also lose their branchier and acquire extremities but preserve the tail. Third the branchifera which always preserve their branchier they resemble those urodella in which development had been arrested while yet in the tadpole state. Fourth the apoda or Cecilia which also lose their branchier but never acquire extremities until lately they were classed amongst the Ophidians in the name of Naked Serpents or Nuda. Family of Enora This family is composed of frogs, toads and some other reptiles having nearly the same form. In them the metamorphosis is more complete than in all other animals of this order. When a young tadpole first leaves the egg it resembles a little fish and can live only in water. Its head is very large, its belly protuberant and its body unprovided with extremities is terminated by a compressed tail which afterwards becomes elongated and much raised. Its mouth is still a small scarcely perceptible hole and its branchier consists only of a tubercle placed on each side of the posterior part of the head. These appendages very soon become lengthened and are divided into shreds. The eyes are perceptible through the skin and a transverse slit appears under the neck so as to form a sort of membranous aperculum. A little later the branchier become ramified and the lips are covered by a sort of horny beak by the aid of which the animal fixes itself to vegetables that form its chief food. But this state does not last long. At the end of a few days the branchial fringes which float on each side of the neck, disappear and respiration is carried on by the assistance of small vascular tufts placed along four cartilaginous arches situate under the throat and pertaining to the hyoid bone. A membranous tunic covered by the skin envelops these internal branchier to which the water arrives by the mouth passing through the intervals of the arches of the hyoid bone. Finally after having laved these organs this liquid escapes by one or two external slits the situation of which varies a little according to the species. The respiratory apparatus then as we have said above exactly resembles that of fishes. Sometime afterwards the posterior extremities of the tadpole show themselves and are developed little by little. They attain considerable length before the anterior extremities are perceived. The latter are developed beneath the skin which they penetrate at a later period. About the same time the horny beak falls off leaving the jaws unencumbered the tail begins to waste away the lungs are developed and in proportion as these organs become more exclusively the seed of respiration the branchii fade and disappear. The cartilaginous arches which supported them are also in part absorbed and finally the tail entirely disappears. The little animal assumes the form which it preserves through life and completely changes its regimen. From being at first herbivorous it gradually becomes exclusively carnivorous and in proportion as this metamorphosis advances the intestinal canal from being long slender and spirally folded becomes short almost straight and swelled to form the stomach and colon. The period of these changes varies from about four to eight weeks according to the species and it has been ascertained that different circumstances may considerably hasten or retard the complete metamorphosis of the young animal. A deficiency of heat and light very much prolongs the duration of the tadpole state. Having reached their perfect state the enora cease to be aquatic animals but most of them continue to live in the neighborhood of water and dive frequently in it. They may not remain during the warm season constantly in the water even though they come freely to the surface to breathe the air. Pulmonary respiration is not then sufficient for them and they require the action of the air on the skin. In winter however this cutaneous respiration is not only sufficient to sustain life but they can remain several months in the water without coming into the air. All these reptiles have a thick set body a flat head, the muzzle more or less rounded very wide mouth, short four feet terminated by four toes and the hind feet are longer and sometimes possess the rudiment of a sixth toe. Their eyes are ordinarily furnished with three lids but sink into the head on slight pressure because the orbits are separated from the mouth only by membranes. A cartilaginous plate occupies the place of a tympanum and causes the ear to show externally. The tongue is generally soft and contrary to what we see in most mammals it is fixed to the edge of the jaw only by its interior extremity so that it can be folded backwards or turned out of the mouth. Finally the skeleton of these reptiles is entirely unprovided with ribs and the inspiration of air can be affected only by a movement analogous to that of deglutition in which the animal dilates the throat to fill it with air then closing the posterior nostrils with the tongue contracts the muscles of the swallow and forces this fluid to enter the lungs. To throw one of these animals into a state of aphyxia it is only necessary to keep the mouth open for a certain time. The frogs, rhino, have the body more tapering than other anora. The hind feet are very long, very strong and more or less palmate which enables them to swim and leap well. The skin is smooth and the males have on each side of the neck beneath the ears a thin membrane which becomes inflated when they croak. They are distinguishable from toads by a row of very fine small teeth all around the upper jaw. These reptiles ordinarily keep on the banks of ponds and rivulets and precipitate themselves into the water on the slightest danger. They feed only on living prey and eat the larva of aquatic insects, worms, small mollusks and flies. In winter they bury themselves in the mud or in holes and do not eat. We give the name of tree frogs, Hila, to Batrachians which do not differ much from frogs except that the extremity of each one of the toes is enlarged and rounded into a sort of viscous pellet or ball that enables them to adhere to bodies upon which they climb and to ascend trees. Endowed with great suppleness and agility tree frogs travel very lightly on the most flexible branches. During the whole summer they live in this manner on trees pursuing insects. Yet in winter they retire to the bottom of the water like frogs do not return again to the humid woods in the spring till after they have deposited their eggs. The common tree frog, Rana arborea, is an apple-green above and pale beneath with a black and yellow line along each side of the body. The toads, Bufo, have a thick set body covered with warts or papillae from which exudes a viscid humor. On each side of the neck there is a large projecting gland called paratid, full of pores which secretes an acrid humor. Their hind legs are not so much elongated as those of frogs and they leap badly. In general they creep rather than walk and when surprised instead of taking to flight they stop suddenly and inflate the body so as to render it hard and elastic and cause the skin to pour out a white humor. Sometimes they endeavor to defend themselves by biting but their mouth is unprovided with teeth and their bite is not venomous as is generally supposed in the country. These hideous and disgusting reptiles ordinarily conceal themselves in shady humid places from which they do not go out except at night or immediately after the warm and abundant rains of summer. Like frogs they feed on small mollusks, worms and living insects but they are more terrestrial in their habits. They butake themselves in summer only to pools and streams where the females resort to deposit their eggs. In countries where the winter is cold they pass the season benumbed in holes. Their respiration then becomes extremely limited and the contact of a very small quantity of air with the skin is sufficient to maintain their existence. When placed in situations where ordinary evaporation is very inconsiderable they can live in this way for a very long time. This explains how it is that toads which have been enclosed in plaster or shut up in holes excavated in stones are often found alive after being many months in confinement. Curious experiments have been made with a view of ascertaining the fact which had been often observed but generally treated as fabulous by naturalists of the existence of living toads and walls and hollow trees and even in the interior of rocks where they had probably remained for years without being able to escape. Laborers who work in quarries have often met similar instances on breaking blocks of stone and they pretend that the toad is found enclosed in the stone on all sides as in a solid mold which would lead us to suppose that it had formed around the body and that the seclusion of the reptile dated from a very remote antiquity. But this opinion is inadmissible and everything leads us to believe that in such cases the retreat of the toad communicates externally by some hole which had been accidentally closed or had escaped observation. The peepas are still more hideous than the toads. Their body is more flattened, the head triangular, their eyes very small, their hind legs short and their anterior toes split at the end into three or four small points. The tongue is entirely wanting. The species best known which inhabits the warm and humid parts of South America is celebrated on account of the manner in which its young are developed. The male places the eggs on the back of the female who immediately takes to the water where the skin irritated by the contact of these bodies swells and forms cells in which the young are hatched and remain until they have completed their metamorphosis. Then the mother returns to land. Family of Eurodella The metamorphosis of betraccions of this family is less complete. For in the perfect state they still preserve the long tail which in the preceding family only exists in the tadpole. At the time of escaping from the egg they are without feet and respire by bronchie which are in the form of tufts and three in number. They are placed on each side of the neck and float externally. As in the Enora their extremities appear successively but the four feet make their appearance before the posterior and to complete the transformation of the tadpole the lungs are developed and the bronchie disappear. In the adult state these animals have nearly the same form as lizards but their head is flattened and we do not perceive the tympanum externally. Both jaws and the palate are armed with small teeth. Their tongue is placed as it is in frogs. The skeleton has rudimentary ribs and the number of their toes is four in front and almost always five behind. Some authors designate these animals under the name of salamanders. Tritons or aquatic salamanders are the most common protractions of the family of Urodala. They always preserve a laterally compressed tail and pass nearly all their time in the water. The most remarkable faculty possessed by these reptiles is the astonishing facility with which they repair any mutilation to which they may be subjected. They not only replace the tail after it has been cut off as is the case also with lizards but their extremities are reproduced in the same manner. The same extremity after having been cut off has been reproduced in tire with its bones, its muscles, its vessels and nerves several times in secession and we are even assured that in one experiment the eye after having been extirpated was reproduced in the space of a year. Several species are found in the neighborhood of Paris. Sometimes the tadpoles become very large before losing their brinquie. A fossil found in the schists of Ennegan and belonging to a large species of salamander has excited a good deal of interest because from a singular error it was for a long time regarded as the skeleton of a fossil man. Salamanders, properly so called or terrestrial salamanders in the perfect state have a round tail and only remain in the water during their tadpole existence or when they lay. They are hatched before they are laid and the young at first have a compressed tail like ordinary tadpoles. They lose the tail and finish their metamorphosis very promptly. In the perfect state they inhabit shady, humid situations. They are ordinarily found under stones or in subterranean holes. It was for a long time believed that salamanders had the power of resisting the action of fire but this fable was without foundation except perhaps that when the reptile is irritated it sweats a milky humor. This humor appears to be poisonous to feeble animals but the salamander is not as is supposed among certain country people an injurious animal. There has been discovered in America a large protraction of the precise form of the salamander that has an orifice on each side of the neck but which it is supposed never has branchier. It is probable however that these organs exist in the first periods of life but disappear at an early date as is the case in the terrestrial salamander. These reptiles which form the genus Monopoma inhabit the great lakes and rivers in the interior of South America. The amphiuma which inhabit the same continent possess the same mode of organization but their body is excessively elongated and their extremities are but little developed. The number of their toes varies from two to three according to the species. Family of Brankifera This family is composed of protractions that always preserve their branchier and resemble the tadpoles of protractions of the family of Eurodela. They have been regarded for a long time as being in fact the young of some large species of salamander but now there is no doubt of their being perfect animals and what is very remarkable is that these branchier they also have lungs and are consequently completely amphibious. These branchier which are placed in the ordinary situation have the form of tufts more or less ramified and float externally in the water. Their lungs are sometimes provided with a vascular network as well developed as in any reptile while in others their structure is very simple. The body of these animals terminates in a long vertical tail but little developed and often are partly wanting. Four genera are known namely the axolotus, the menobronchus, the proteus and the siren. The axolotals axolotus in every respect resemble the tadpoles of salamanders that have acquired their four paws. Only a single species has yet been discovered. The axolotl of the Mexicans siren pisciformis is the lake in the mists of which stands the city of Mexico. The menobronchus also have four feet but instead of having four toes before and five behind they have only four throughout. The proteans proteus have but three toes in front and two behind. The only species known proteus anguinus more than a foot long and only as thick as the forefinger is found in the subterranean waters of Mexico. Its skin is smooth and whitish its muzzle is elongated and depressed and its eyes are exceedingly small and concealed beneath the integuments. The sirens have interior extremities only and in the elongated form of their body resemble eels. Three species are known one of which attains three feet in length and inhabits the marshes of Carolina. Family of apota The apota cilia as we have already stated are entirely without extremities and until lately have been regarded as serpents but it has been ascertained that in early life they have bronchiae which show themselves through a hole on each side of the neck. In the adult animal we find even the arches of the hyoid bone which serve to sustain these organs. The body is very nearly cylindrical the skin is smooth and transversely furrowed by annular wrinkles at first sight it appears to be entirely naked but on dissection we find in its thickness rows of small and extremely thin scales situate in these wrinkles. The eyes which are very small are concealed beneath the common integuments and sometimes they are entirely wanting. These animals are completely apotis that is without feet and their skeleton like that of serpents has two long rows of ribs but these bones are much too short to surround the trunk and on the other hand we remark in the mode of articulation of the vertebrae and in the disposition of their jaws many characters which approximate them to the latter batrachians These reptiles which establish a passage between the batrachians and ophidians inhabit humid and shady places dig holes in the ground and seem to feed on vegetable substances as well as on worms and small insects They are found in South America The class of fishes comes next in order End of Lesson 4 Lesson 5 of The Elements of Herpetology and Ictheology This is a LibriVox recording All LibriVox recordings are in the public domain For more information or to volunteer please visit LibriVox.org The Elements of Herpetology and Ictheology by William Ruskenberger Lesson 5 Class of Fishes General Characters Form Integuments Skeleton Muscular Apparatus Swimming Bladder Senses Apparatus of Digestion Circulation Habits Fishing Classification The fourth and last class of the branch of vertebrate animals comprises the fishes That part of natural history which treats of them is termed Ictheology from the Greek Icthas, a fish and Logos, a discourse These animals, as everybody knows, are destined to live underwater and this circumstance has impressed upon them a peculiar organization But the most important differences they present when compared with other vertebrata consist in the confirmation of the apparatus of respiration and circulation They never have lungs and always breathe by branky eye only Their heart has but two cavities and only receives venous blood which, after being in contact with oxygen enters a dorsal vessel where no new motive force accelerates its course to different parts of the body Therefore their circulation is not as active as it is in the superior animals and like that of reptiles their blood is cold Their skin is naked or covered with scales only They have no mammy like the mammalia and are reproduced by the means of eggs Their extremities are in the form of fins The external form of fishes varies but their body is generally all of a piece The head, which is the size of the trunk is not separated from it by a narrowing like the neck of the superior vertebrate animals and the tail owing to its size at the base is not distinguishable from the rest of the body Some of these animals are entirely without fins but in most of them we find a considerable number of these organs Some placed on the middle line of the back or belly and consequently unpaired or singly and others on the side arranged in pairs The latter represent the extremities of other vertebrate animals the anterior extremities which correspond to the arm in man and the wing in birds are fixed on each side of the trunk immediately behind the head and are called pectoral fins The abdominal extremities less distant from each other generally occupy the inferior face of the body and may be placed more forward or backward from beneath the throat to the origin of the tail They are called ventral fins The single or unpaired fins occupy, as we have just said, the middle line of the body and are distinguished into 1st dorsal, 2nd dorsal anal and caudal fins according to their situation on the back, under the tail or at its extremity They are all nearly of the same structure and almost always consist of a fold of the skin sustained by bony cartilaginous rays very much in the same manner that the wings of bats and dragons are sustained by the fingers or toes or by the ribs of those animals We also observe on the external surface of the body large slits placed on each side immediately behind the head which serve as an outlet to the water which has laved a cranky eye They are openings of the gills Generally there is but one on each side and their anterior edge is movable and resembles a shutter Along the whole length of the body on each side there is a series of pores which form what ethiologists call the lateral line The skin is sometimes nearly covered but is almost always covered with scales Sometimes these scales are in the form of rough grains Sometimes they are very stout tubercles or plates of considerable thickness But in general they are very thin lamellae covering each other like shingles or tiles and lead into folds of the skin They may be compared to our nails though they contain more calcareous salts The colors with which these animals are adorned are astonishing in their variety and brilliancy Sometimes they can only be compared to the most glittering, gold or silver Sometimes they present the richest tints of green blue, red or black The silvery matter which frequently gives them such a beautiful metallic luster is secreted by the skin and is composed of a multitude of small polished plates The skeleton of fishes is ordinarily bony but in many of these animals it always remains fibro cartilaginous or cartilaginous and in some this frame possesses even less solidity and remains absolutely membranous In this respect they form the connecting link or passage between the vertebrate and invertebrate animals The bones never have a medullary canal and the cartilage which constitutes their bases is not like that of mammals and birds for when boiled in water it does not yield the skeleton The skeleton is composed of a head to which is joined a highly developed hyoid apparatus serving for respiration a trunk and extremities The structure of the head is very complicated We first observe a middle portion composed of a great number of bones joined together by sutures and forming a sort of immovable keel to which are suspended the bones of the jaws, cheeks etc This middle portion the form of which is that of a pyramid with three sides with its summit directed forward presents posteriorly the cranial box or skull in which is lodged the apparatus of hearing as well as the brain its middle part is hollowed out to form the orbits and in front we find pits which belong to the olfactory apparatus There are bones which correspond to those of the heads of mammals but most of these bones in fishes are composed of several pieces which never run together into one as happens at an early age in the mammalia and birds At the anterior extremity of this portion of the head we find the upper jaw which is sometimes immovable though it generally preserves great mobility On each side there is an intermaxillary bone placed near the middle line and a lower jaw bone which extends laterally and moves upon the first Besides these parts we find the upper jaw Besides these parts we find a very considerable apparatus designed to afford attachment to the brankii or to protect them composed in part of the hyoid bone which is covered on each side by a sort of cover or door called operculum or gill cover The vertebral column which is continuous with the head is divided into two distinct portions one dorsal and the other caudal The body of the vertebrae has a peculiar form It is hollowed before and behind by a conical cavity These two hollow spaces are sometimes joined so as to form a hole and the double conical cavity arising from the junction of two neighboring vertebrae is filled by a soft substance The ring destined to form a passage for the spinal marrow is surmounted by a spinous process and on each side there is a more or less distinct transverse process which over the cavity of the abdomen extends outwardly and articulates with the corresponding rib but in the caudal portion of the spine it is directed downwards and often forms with its fellow of the opposite side a ring from the lower part of which arises a long spinous process similar to that which is situated on the dorsal face of the vertebra The ribs are sometimes wanting At other times with the whole abdomen and in a small number of fishes they are fixed to a series of unpaired or single bones which should be regarded as the sternum They frequently sustain one or two stylists which have an outward direction and penetrate the flesh Sometimes there are similar stylists arising from the bodies of the vertebrae but once it is that in certain genera such as herrings fish bones become so numerous On the middle line of the body we also find a certain number of bones called interspinal which generally rest upon the ends of the spinous processes of the vertebrae and by their opposite extremities articulate with the rays of the middle fins These rays are sometimes pointed bones called stings or spines Sometimes they are stalks or stems bony only at the base formed of a multitude of small articulations in continuation and often branched towards the end These last appendages are called soft or articulated rays They always form the caudal fin and sometimes there are no others The lateral fins which represent the extremities are terminated by rays similar to those of the vertical fins and analogous to fingers At the base of the pectoral fin we find a series of from four to five small flat bones comparable to the bones of the carpus which in their turn are attached to two flat bones which seem to be the radius and ulna enlarged This apparatus is supported on a species of bony belt situate immediately behind the gills and on which the operculum applies It consists of a series of three bones One is a cranium to the hyoid apparatus and supports posteriorly a long stylet The principal piece that enters into its composition is that which supports the forearm which may be compared to the humerus It joins below with that of the opposite side and with a middle and is attached to the cranium through the medium of two bones which Cuvier considers analogous to the scapula Finally, the stylet which arises from it and is prolonged backwards upon the ribs is ordinarily formed of two pieces and may be compared to a coracoid bone The posterior extremity is less complicated The rays of the ventral fin are supported by a single bone generally triangular which often becomes attached in front to the middle junction of the bony belt of the pectoral extremity and at other times it is merely suspended in the flesh In cartilaginous fishes the arrangement of the skeleton differs from what has just been described The head especially is much more simple in its structure The muscular apparatus is composed of muscles destined to flex the vertebral column laterally and also to move the tail They form the largest part of the mass of the body of fishes By striking the water laterally by alternate flexions of the trunk and tail these animals communicate to their body nearly the whole of the rapidity they have in swimming Their vertical fins serve to increase the extent of the species of keel or ore they form While the chief use of the pectoral and ventral fins in general is to influence the direction of their course and to maintain the equilibrium of the animal A peculiarity of their organization which is of great assistance in swimming is the existence of a sort of pouch filled with air and so placed that it can be compressed at will This swimming or air bladder which is placed in the abdomen beneath the dorsal spine ordinarily communicates with the esophagus or stomach by a canal through which the air contained in it may escape But this fluid does not seem to enter by that route It is produced by secretion the seat of which is in a portion of the parieties of the reservoir itself which is of a glandular structure By the motions of the ribs this bladder is more or less compressed and according to its volume it gives to the body of the fish a specific gravity equal superior or inferior to that of the water and causes it thus to remain in equilibrium to descend or ascend in this liquid It is remarked that it is often wanting and that it is very small in those species that swim near the bottom or bury themselves in the mud In a small number of fishes the pectoral fins are so very much developed as to enable the animal to sustain itself in the air for a few moments when it springs out of water There are some also that by crawling or by frequent leaps it is possible of progression on land It is asserted that some can climb trees but instances of this kind are very rare Fishes pass their lives almost entirely in providing for their subsistence or in escaping from their enemies Their external senses seem to afford them only very dull impressions and their faculties are of the most important Fishes are very stupid animals They have no remarkable intelligence or instinct and their brain is but little developed It does not entirely fill the cavity of the cranium and is surrounded by a liquid matter of a fatty nature The air of fishes in general is composed only of a vestibule surrounded by three memberness on my circular canals suspended in the cavity of the cranium on each side of the brain into which waves of sound are communicated only after they have set in vibration the common integuments and bones of the cranium Generally there is no appearance of an external ear Their eyes are ordinarily very large and are unprovided with its true eyelids and a lacrimal apparatus The skin which covers them is transparent and the iris is silvery and immovable or nearly so and the cornea is almost flat The pupil is very large and the crystalline lens is spherical The nasal faussy do not open into the pharynx as is the case in vertebrate animals that breathe air The tongue is never truly fleshy and the sense of taste is but little developed Tat must be extremely obtuse In general the skin of these animals is entirely covered with scales sometimes however it is naked Ordinarily fishes are very voracious and are not very particular in the voice of food The species which live chiefly on vegetables are very few in number They are almost all carnivorous and devour each other Fishes sometimes have teeth not only in the jaws but also in all the bones that surround the cavity of the mouth and that of the pharynx At other times they are entirely wanting and their teeth never have roots and their form varies very much particularly those that are found on the pharyngeal bones and which serve to grind the food when on its way to the esophagus They have no true salivary glands The esophagus is very short The other viscera of the digestive apparatus are lodged in the abdomen which is lined by a peritoneum and separated from the cavity containing the heart by a sort of diaphragm In some fishes chiefly the cartilaginous fishes the abdomen communicates externally by two openings situate upon the sides of the anus so that the peritoneum is continuous with the skin The stomach is in general very distinct that part which corresponds to the large intestine is not much larger than the small intestine and there never is a cecum as in mammals The liver is generally large and of a soft texture The position and size of the gallbladder vary The place of the pancreas is almost always supplied by two tubes of peculiar tissue placed around the pylorus The position of the anus varies much Sometimes it is found under the throat and at others at the base of the tail The kidneys are very voluminous and extend along both sides of the vertebral column the whole length of the abdomen Their excretory ducts terminate in a sort of bladder the opening of which is posterior to the anus Digestion seems to be carried on very rapidly and the chyle is absorbed by numerous lymphatic vessels which empty by many trunks into the venous system near the heart The blood of fishes is red The globules are elliptical in form and of considerable size The heart is placed under the throat in a cavity separated from the abdomen by a sort of diaphragm as we have just said and protected by the pharyngeal bones above by the arches of the brachii on the sides and generally by the humeral syncture behind It is composed of an oracle which receives the venous blood extracted in a large sinus a kind of large vein situated near it and of a ventricle placed below and giving origin at its anterior extremity to a pulmonary artery the base of which is inflated and constitutes a contractile bulb This vessel soon divides into lateral branches which are distributed to the gills and the blood after traversing these organs goes to the head through another vessel which also runs along the arches of the brachii There these canals send some branches to the neighboring parts and unite to form a great dorsal artery which is directed backwards beneath the spinal column and sends branches to all other parts of the body but all the venous blood does not go directly into the sinus mentioned above that of the intestines and some other parts before returning to the heart is carried through the liver by the vena porta We see now that the blood in passing through the circulatory circle entirely traverses the respiratory apparatus as in mammals and birds but it only passes once through the heart which must render its progress slower The heart itself corresponds in its functions to the right half of the same organ in the superior vertebrate animals Respiration is affected by means of the air which is always found dissolved in the water and takes place on the surface of a multitude of very vascular and projecting lamellae attached to the external edge of the brachial arches Generally there are on each side four brachii each composed of two rows of elongated lamellae In most of the cartilaginous fishes there are five and in the lamprey we find seven In almost all the bony fishes these lamellae are simple and only attached at their base In a small number they are on the contrary ramified and in the form of tufts Finally, in most cartilaginous fishes they are attached to the skin by their external edge as well as to the arches of the brachii by their internal edge The water necessary for respiration reaches the mouth and by an act of swallowing passes through the slits left between the brachial curves or arches and in this way reaches the brachii laves their surfaces and then escapes through the openings of the gills We see in fact the animal open its mouth and elevate the operculum alternately In fishes in which the brachii are free on their external edge one of these openings on each side is sufficient but when the brachii are fixed there is required as many openings as there are spaces betwixt the brachii Consequently we are made acquainted with the arrangement of the respiratory apparatus by simply inspecting the external openings Fishes consume a very moderate quantity of oxygen Some however are not content with what is dissolved in the water and visit the surface from time to time to breathe the air There are some indeed that swallow it and by causing it to pass through the intestine convert the oxygen into carbonic acid When fishes remain out of water they generally perish very quickly asphyxia Not for the want of oxygen but because the brachiolemeli being unsustained by the water are effaced and do not permit the blood to pass readily through them and because these organs by drying become unfitted for performing their functions Therefore those fishes that perish most promptly from exposure to the air have widely opened gills which facilitates evaporation from the brachii while those that resist this exposure best have these openings very narrow or even possess some receptacle in which they preserve water for moistening these organs As we have already stated fishes produce scarcely any heat but some of them possess the singular faculty of producing electricity and of giving very powerful shocks to animals that touch them The torpedo the solaris and the species of gymnatus are of this kind and what is very remarkable the conformation of the electric organ differs in each one of them To the simultaneous development of an incalculable number of eggs deposited in the same place and the instinct that induces different fishes to follow each other we must attribute the assemblage of certain species in immense and close legions called by fishermen shoals of fish In fact, we cannot well term these assemblages companies or societies The individuals composing them do not aid each other from having the same necessities to satisfy they keep in the same locality or abandon it and if we sometimes observe one among them followed as a leader it probably arises from a tendency to imitation which always accompanies the first donnings of reason it may be astonishing to some to speak of the reasoning of a fish an animal that is proverbial for its stupidity but if we study the habits of these beings in our fishponds we shall see that when they swim tranquilly without any determined aim they pass side by side without seeming to pay attention to the motions of their companions but if one of them suddenly perceiving a bait hastens its course and swims swiftly in a determined direction we frequently observe that the other fishes even those that are placed so as not to perceive the object of attraction at once follow in the crowd to profit by the discovery now this instinct of imitation resembles simple reasoning it is true but consecutive may we not suppose that these animals attribute the rapid course of their companion to some circumstance of a nature to interest them also to the discovery of some danger they ought to avoid or to some bait he rushes to devour and it is for this reason they hasten in pursuit and is not this the case everywhere even among men and is not the instinct of imitation which produces so many good and evil actions a consequence of this tendency to profit by the results of the observation or judgment of another and to attribute to the actions of those who seem to be moved by a powerful impulse an object that it would be equally desirable for all to attain whatever it may be these animals thus assembled in troops often make long voyages either to gain the open sea or to ascend rivers or to change their latitude certain fishes lead an almost sedentary life and always remain in the same locality where they were born others are always roaming and a great many of these animals make periodical voyages of greater or less extent in the cold season they ordinarily approach the coast or into rivers and in this way make long passages every year about the same period shoals of migratory fishes arrive in the same places and it is generally believe that many of these species regularly migrate from the north towards the south and from the south towards the north pursuing a determined route perhaps it would be more correct to believe that when they disappear from the shore they only retire to the great depths of the sea according to their habits fishes are divided into marine and fluviatile there are some too that alternately frequent salt and fresh water and the nature of this fluid seems to exercise less influence upon them that is generally believed for some essentially marine fishes have been successfully reared in reservoirs of fresh water the number of these animals is immense and as they furnish man a wholesome and agreeable element fishing is an important branch of industry among the most savage as well as among the most civilized people the Romans who after the loss of their liberty displayed such boundless luxury in the table did not confine themselves to sending fishing vessels to the neighboring seas and to receiving fishes from the Ionians of the fish car which is a kind of floating reservoir for keeping fish alive but better to secure the supply the wealthiest citizens constructed immense fish ponds filled with seawater in which they deposited the most delicate fishes of Sicily and even of Greece and Egypt the first person who built one of these great depots was Lucius Murina so named from the care he took of the Murina or eels he had numerous imitators and was even surpassed in his follies by Lucullus who cut through a mountain near Naples to introduce the seawater into his ponds and hollowed the rocks which surrounded them into caverns to afford his fishes a cool retreat during the heat of summer other great personages of the ancient capital of the world prided themselves on possessing fishes so tame as to suffer themselves to be touched we are assured that Crassus was more distressed upon losing one of his eels than upon the death of his three children and history relates the curious moments of a Roman lady going into mourning on account of the death of a favorite Murina to give an idea of this strange taste of those degenerate Romans for fish of every kind we will mention a supper given to the emperor Arthur by his brother at which there were served two thousand plates of rare fishes the fact that one Vides Palio a particular friend of Augustus took delight in throwing his slaves in the eel vats for the pleasure of seeing them torn to pieces and devoured on a particular occasion the emperor honored Palio with his company at a brilliant entertainment at which a slave unfortunately happened to break a costly crystal vase the unfeeling master in a paroxysm of fury exclaimed to the other attendants away with him to the Murini the poor wretch almost dead with horror fell at the feet of the emperor beseeching that he might be permitted to die some death less terrible astonished at the sudden and strange circumstance Augustus made speedy inquiry into this extraordinary mode of punishment and when he fully understood the savage cruelty disposition and practice of Palio ordered at once all the remaining vessels broken before his face directed the reservoirs to be filled up gave freedom to the pleading slave and only consented to spare the life of the murderer his master in consideration of his former regard natural history of the fishes of Massachusetts by Jerome V.C. Smith MD modern times have not witnessed similar follies but nevertheless for many maritime people fishing has not been the last a source of great wealth at one period not very remote from our own this branch of industry employed one fifth of the total population of Holland and in the herring fishery alone that country covered the whole North Sea with her vessels in England it subsisted a considerable number of good and hardy sailors and even in France where it is of less importance there are from 30 to 40,000 fishermen about one third of whom venture as far as the coasts of Iceland and Newfoundland and in the United States a very large number of people derived their living from the various fisheries the immense class of fishes is naturally divided into two series the Osseus and cartilaginous fishes which differ from each other not only in their skeleton but also in a great number of other characters the modification of the structure of the branchy eye the disposition of the mouth and the nature of the fin rays that sustain the dorsal fin as well as the position of the ventral fins furnished naturalists with the basis for the division of the two groups into orders End of Lesson 5 Lesson 6 of The Elements of Herpetology and Ictheology This is a LibriVox recording All LibriVox recordings are in the public domain For more information or to volunteer please visit LibriVox.org Recording by Lauren Hough The Elements of Herpetology and Ictheology by William Rueschenberger Lesson 6 Order of Akanthopter regions Family Percoides Purchase Rockfish Family of Meloides Red Mullets Flying Fishes Family of Maled Cheeks Family of Cyanoides Family of Sporoides Family of Menides Family of Squamapenies Family of Labyrinthiform Pharyngeals Family of Scamboroides Mackerel, Mackerel Fishery Toony Swordfish, etc. Division of Osseous Fishes Order of Akanthopterygi The Order of Akanthopterygians is easily recognized by the disposition of the Branqui and Upper Jaw and by the Spinas Finns 3 fourths of the fishes known belong to this group but these animals resemble each other in so very many respects that in spite of the numerous differences we remark among them we can only separate them into several natural families, all of which we are obliged to place in the same order The first fin rays of the back are always bony and spinous When there are two dorsal finns these spinous rays only sustain the first and when there is but one of these organs they sustain at least its interior portion and we sometimes find them entirely free or separate Generally there is also a bony ray to each ventral fin and frequently the anal fin has some spines for its first rays This order is divided into six natural families the most remarkable of which are the percoides, the miloides the mailed cheeks the labyrinthiform pharyngeals and the scomboroides The family of percoides or fishes that resemble a perch is composed of fishes that have an oblong more or less compressed body covered with scales which are generally hard the mouth large and armed with teeth situate upon the front of the vomer and almost always on the palate bones as well as the jaws, the branchial arches and pharyngeal bones the aperculum or the bone situate immediately anterior to it and therefore called pre-aperculum or anti-aperculum is dentate or spiny on its edge and the fins are always seven or eight in number they have no beards upon the chin in general they are adorned with beautiful colors and their flesh is very agreeable food Most of these fishes have the ventral finns attached beneath the pectoral those in which this arrangement occurs are the name of thoracic percoides they are subdivided into two groups characterized by the number of the soft rays of the ventral finn which is five in the one and seven in the other Among the first are those that have seven branchiostegous rays the small, thin and elongated bones which sustain the gill membrane situate beneath the aperculum and serving to complete the external parieties of the branchial cavity two dorsal fins and all the teeth very fine and close like the pile on velvet the perches, the rockfish, etc the perches, perca are distinguished by their smooth tongue and by the spines and teeth on their apercula they inhabit fresh water the common perch, perca fluviatilis which is greenish with vertical blackish bands and the ventral and anal fins red is found throughout Europe as well as a great part of Asia in the United States it inhabits lakes, rivers and running streams and avoids salt or brackish water and ordinarily keeps at a death of two or three feet these fishes do not swim in numerous shoals they feed on worms, insects and small fishes they spawn in the month of April and their eggs are joined together by a viscid matter in long cords which interlace among reeds, etc the rockfish or striped bass percalabrax is a sea fish that has the tongue covered with asperities and the apercula somewhat different but which in other respects closely resembles the perches on the sides are parallel lines like narrow ribbons, eight in number which give it the name of striped bass the scales are large of a metallic luster and the aperculum is serrated in the middle plate this fish abounds on our own coast and is much esteemed as an article of food the family of maloides differs but little from that of the percoides but is easily distinguished from it by the large scales with which the whole body of these fishes is covered and by two long seri or beards which hang from under the lower jaw it is composed of the mullets properly so called of which two species are found in Europe namely the red mullet and ser mullet the red mullet, mullis barbatis has the body and tail red even after the scales have been removed its size is ordinarily from 8 to 10 inches it lives in many seas particularly in the Mediterranean and is much prized for the excellent taste of its flesh it is celebrated on account of the pleasure which the Romans took in contemplating the changes of color it displays while dying exorbitant prices were paid for mullets of extraordinary size and at entertainments they were brought to the table alive and cooked before the eyes of the guests the ser mullet, mullis ser mulletis is larger than the mullet and is longitudinally striped yellow it is more common in the ocean but its flesh is less esteemed the family of mailed cheeks bucci liricati is recognized by the manner in which the suborbital bones are prolonged to the apercula and protect the cheeks in this family are placed the flying fishes, dactylopteris in which the pectoral fin rays are very numerous and united by a membrane so as to form very large pectoral fins which they use as wings to sustain themselves in the air when they spring out of water in the hope of escaping from their enemies voyagers meet with them in the Mediterranean but particularly in the tropical seas they swim in numerous shoals which the bonita and other voracious fishes fiercely pursue and when to escape this danger they spring into the air another not less great awaits them for a host of sea birds such as the frigate also pursue them and embrace this opportunity to pounce upon them these fishes cannot go very far in this way because the drying of the membrane which unites the rays of the pectoral fins forces them soon to fall back again into the sea the family of cyanoidies resembles the percoides but is distinguished from them by the absence of teeth on the vomer and pallet in general the bones of the cranium and face are cavernous and the muzzle is more or less inflated almost all the fishes of this group are good to eat and many of them are exquisite to this family belong the umbrina which is a large good fish the carvina which is found in the Mediterranean and the drum fishes or pagonias which inhabit our own coast the last are remarkable for the noise they make which is compared to that of a drum the family of spheroides has neither the inflated muzzle nor spineoperculum of the proceeding but the pallet is free of teeth and the body is covered with scales of greater or less size and the mouth is not protractile in the first tribe of this family called sparis we find on each side of the jaws round molar teeth in form of paving stones sometimes there are also in front of the jaws two cutting incisor teeth almost similar to those in man it is the case in the sargis some species of which live near the Mediterranean coasts at other times we only find in front some conical or blunt teeth the dorades, chrysophagus are recognized by this latter character and by the existence of at least three rows of molar teeth in the upper jaw the common dorade is frequent on the coast of britney as well as in the Mediterranean its body is oval and its mouth furnished with four rows of molar teeth above and five below it derives its name from its golden color the small family of menides is composed of fishes that very much resemble the spheroides but which are distinguished from them by the mouth which is very protractile and at the will of the animal converted into a tube the family of squama pennies are recognized by having the soft and sometimes the spinous part of the dorsal and anal fins covered by scales and difficult to distinguish from the mass of the body which is compressed and also scaly some of the cyanoidies also have the fins encrusted with scales but they never have the teeth in the form of flexible bristles as in most of the squama pennies and their inflated muzzle is often sufficient to distinguish them the squama pennies in which the jaws are furnished with several ranges of teeth similar in conformation and arrangement the jaws of a brush have been united under the name of ketodon their mouth is very small and the dorsal and anal fins are so covered with scales that it is difficult to distinguish them from the body they are very numerous in the seas of hot regions and very remarkable for the beauty and variety of their colors the castagnolis brama and the archers tohotis, etc differ from the ketodons in many respects particularly in having teeth on the vomer and palate the first have the muzzle very short the forehead vertical and a very small number of spinous rays concealed in the anterior portion of the dorsal fin they inhabit the Mediterranean the archers or shooting fishes have the forehead very oblique and the dorsal fin very far back armed with strong spines and not covered by scales the common species tohotis, jaculator inhabits the Ganges and the seas of India it is celebrated on account of the manner in which it projects drops of water on insects that frequent aquatic plants they throw a drop 3 or 4 feet high and rarely miss their aim the singular instinct is common to a species of ketodon that inhabits the same places the family of labyrinthiform pharyngeals is a small family remarkable for possessing very complicated cells above the brachii these cells enclosed beneath the apriculum and formed by the lamellae of the pharyngeal bones serve to retain a certain quantity of water which keeps the brachii humid when the animal is exposed to the air and enables it to live in this way for a considerable time these fishes are in the habit of leaving the rivers and pools their ordinary boat and going to considerable distances by crawling on the grass or on the land those that possess this labyrinthiform apparatus in the highest degree of complication and which have received the name of anabas not only remain a long time out of water but also, as we are assured, climb trees most of the fishes of this family inhabit India and China the family of scomberroides is the most important of this order it comprises many fishes of considerable size the taste of which is excellent and the fecundity so inexhaustible that in spite of the continued destruction to which they are subject they return yearly in immense lesions to the same localities and offer themselves as a certain prey to the activity of fishermen and to the industry of those who make it a business to prepare and preserve them the tunii, the bonita and mackerel which are so useful to man and form a type of this family are easily distinguished from other echanthopterygians but many of the species that are naturally grouped around them possess none of the marks which make them known and establish such close relations with other families that the limits of the latter are difficult to define in general, the scomberroides have very small scales and a large part of the skin smooth they have neither spines nor teeth on the pieces of the opercula their vertical fins are not scaly the tail and the caudal fin especially are ordinarily large and very vigorous most of them have the sides of the tail careenate or armed with scales and in many, the posterior rays of the second dorsal and anal fins are separated and form so many false fins or spurious fins those which possess these last characters and have the dorsal fin continuous form the tribe scomber their body is in the form of a spindle the tail is short and more or less careenate laterally but not armed with shields and the caudal fin is very large they are excellent swimmers this family includes the mackerel, the tunii the swordfish, etc the common mackerel, scomber are distinguished from the other scomberroides by the uniformly small and smooth scales with which the body is covered by two small cutaneous crests situate upon the sides of the tail and by a vacant space that separates the two dorsal fins the common mackerel, scomber scombrus has a blueback marked with undulating black stripes and five false fins it is a migratory fish and at certain seasons abounds on the coast of the United States and Europe the importance of the mackerel fishery originated from the fact that in the state of Massachusetts no less than 308,462 barrels were packed during the year 1830 on the western coasts of England this fishery is conducted with nets at night by torchlight the fishermen spread themselves over several leagues and cast their nets which are sometimes more than a league in extent in the direction pursued by the shoals of mackerel the meshes of the net are of a size to receive the head of a moderate sized fish but arrested by the fins and when it endeavors to extricate itself its gills become entangled and it is held prisoner mackerels are also caught by hook and line the genus of toony, thynus is closely approximated to that of the mackerel from which it is distinguished by a sort of corselet around the thorax formed of scales which are larger and not so smooth as those on the rest of the body the common toony, scomber thynus resembles the mackerel in the general form of its body but it is rounder and attains a larger size in general its length is 3 or 4 feet but sometimes it attains to more than 15 this fish is sometimes seen in the ocean but it abounds especially in the Mediterranean at certain periods it coasts along the shores in innumerable legions and gives rise to very important fisheries which have been carried on in the Mediterranean from the remotest antiquity and constitute a chief source of the wealth of province, sardinia, etc one of the most remarkable modes of taking the toony is by what is termed the madrag this name is given to a sort of labyrinth constructed of nets stretched out vertically in the sea and so arranged as to form a series of chambers open from the land side by a sort of door and united by another net which bars the passage and arrests the toonies in their periodical course along the shore these fishes at first pass between the shore and the chambers destined to receive them but arrested by the net mentioned above they turn towards the high sea and enter the labyrinth where they become confounded and fall in easy prey on the coast of the United States where they do not run in shoals they are occasionally taken in baiting other more common fishes in Europe the flesh of the toony is very much esteemed it resembles beef and is preserved either by the aid of salt or by boiling and immersing in oil the bonita, scombrapalamus celebrated on account of its pursuit of flying fishes in the tropics is a species of toony which may be recognized by the longitudinal brown stripes with which its belly is marked the tribe of sword fishes and all other fishes of the same family by the beak or long sword-like point which terminates the upper jaw and forms a powerful weapon with which these fishes attack the largest marine animals the sword fishes, properly so called syphius are without ventral fins and the prolongation of the muzzle is flattened horizontally and is cutting like a broad sword blade but one species is known syphius gladius which is often 15 or even more feet in length it is more common in the Mediterranean Atlantic, the flesh which is white and compact is delicate this fish is not uncommon near our own coasts and is often taken with the harpoon another tribe called centronitus is characterized by the absence of the membrane that unites the rays of the first dorsal fin which consequently remain free among other fishes belonging to this tribe is the pilot fish, nocrates or scomberductor so called from its habit of following vessels to seize what may be thrown overboard so from the habit attributed to it of conducting the shark which directed by the same instinct also very frequently accompanies vessels at sea with great perseverance they have a fusiform body very small scales, nearly the same as the mackerel and cartilaginous carinae on the sides of the tail like the toonie, the common species is about a foot long, the family of tinioides is composed of acanthopter regions which approximate the scomberoides, they also have very small scales but are distinguished by an extremely elongated body, very much flattened on the sides, the form of which has obtained for them the name of ribbon fishes the family of tutees also resembles the scomberoides it is composed of a small number of fishes the body of which is compressed and oblong with a small mouth but slightly if at all, protractile and armed in each jaw with a single row of cutting teeth, the palate and tongue are without teeth and there is but one dorsal fin the tutees are herbivorous the acanthorii called surgeons on account of a large movable spine sharp as a lancet which they have on each side of the tail with which they inflict severe wounds on those who imprudently take hold of them belong to this family the family of muculoides is distinct from all the proceeding and is characterized by an almost cylindrical body covered with large scales a slightly depressed head and short muzzle, a transverse mouth armed with extremely fine teeth two separate dorsal fins, ventral fins attached behind the pectoral etc they constitute a single genus the mullets, mughil which are much esteemed End of Lesson 6 Recording by Lauren Hough Lesson 7 of The Elements of Herpetology and Ictheology This is a LibriVox recording All LibriVox recordings are in the public domain. For more information or to volunteer, please visit LibriVox.org Recording by Lauren Hough The Elements of Herpetology and Ictheology family of clupii herrings, herring fishing shad, sardines, anchovies, etc Order of Malicoptery GI Abdominalis This division is composed of osseous fishes that have the upper jaw movable simple pectinate brachae the fin-raised cartilaginus their ventral fins are suspended beneath the abdomen and behind the pectoral fins without being attached to the bones of the shoulder. It is composed of five families, namely the Cypernoides comprising those fishes that resemble carp, the SOCs or pikes, etc the Cyloroides the Salmonides, the type of which is the common salmon, and the clupii or herrings and other fishes having the same organization. The Cypernoides Cyprinidae have a slightly cleft mouth, weak jaws most frequently without teeth and a scaly body without an adipose dorsal fin. They are the least carnivorous of the fishes. One of the principal tribes of this family is the Cyprinus, which is composed of freshwater fishes, and includes the common carp, the goldfish, the barbel, the gudgeon, the tench, etc. This group is characterized by the absence of teeth in the jaws by the existence of a single dorsal fin, and ordinarily the scales are large. Most of these fishes feed on grains, herbs, etc. They have in the back part of the mouth a masticatory apparatus for crushing their food. The Carps Cyprinus are distinguished by their long dorsal fin, which, as well as the anal, is provided with a more or less strong spine for the second finray. The common carp, Cyprinus carpio, is found in all Europe but has not yet been met with in the United States. It delights in tranquil waters and is easily reared in rivers and ponds. The duration of its life is very long, and it is exceedingly prolific. When young, the growth of Carps is very rapid, and at six years old they weigh about three pounds. They often attain three or four feet in length. During the winter, they bury themselves in the mud and pass many months without eating. The Golden Carp, or Goldfish, Cyprinus oratus, is reared in garden ponds and vases on account of the beauty of its colors, which are a mixture of black, a beautiful golden red, and silvery white. The Barbals, Barbas, resemble the Carps, but their dorsal fin is shorter. The common Barbal, Cyprinus Barbas abounds in clear running waters and sometimes attains more than ten feet of water. The Guggins, Gobio, also resemble the Carps, but they have no bony spine in the anterior part of the dorsal and anal fins. The mouth is surrounded with siri or beards. There is one species which abounds in the rivers of France, and though small, is much esteemed for its taste. The Tenches, Tinka, in addition to the characters of the Guggins, have very small scales and very short siri. The Common Tench, Cyprinus Tinka, inhabit stagnant waters in France. It is generally of a yellowish brown, attains about a foot in length, and is less esteemed than the Carp. The Bremes, Abramus, have neither spinous fin rays nor siri. Their dorsal fin is short, but the anal is long. Two species are found in France. In the United States, they are small. The Shiner, Cyprinus Chrysolincus, is among the smallest of freshwater fishes, being usually less than an inch in length. Shiners are the prey of their larger neighbors and the sport of school boys that angle for them with a crooked pin. The Mino, Cyprinus Atronassus is another of the very small fishes scarcely exceeding an inch in length. It is found in the Brooks in every part of New England and the Middle States. The Roaches, Luciscus, form several species, all of which are small. The Common Roach, Luciscus vulgaris, acquires 7 or 8 inches in length and is remarkable for its brilliant scales, which are easily detached. They are silvery on the sides and under parts of the body. The Nacreous substance which gives them this metallic appearance is employed in the arts for the manufacture of false pearls. The Suckers, or Loaches, Cobitis, have a mouth unprovided with teeth, but it is surrounded by lips fitted for sucking. Their head is small, the body is elongated, covered with small scales and enveloped in a mucosity or slime. Their ventral fins are very far back and over them is found a single small dorsal fin. The Family of Associes, which comprises the pikes and analogous fishes, has no adipose fin. It is distinguished from the preceding by the conformation of the mouth and the existence of teeth. The pikes, esox, are recognized by their oblong, obtuse, broad, depressed muzzle. They have but one dorsal fin which is placed opposite to the anal and nearly the whole entrance of the mouth as well as the jaws are full of teeth. The Common Pike, Esox, Lucis, is found in the fresh waters of Europe and North America. It is less common in the south than in the north and is everywhere sought for its flesh, which is savory and of easy digestion. It is the most voracious and most destructive of all the freshwater fishes. It devours with avidity frogs, young ducks and all the fishes that come in its way. It often seizes animals larger than itself and its presence in a pond is sometimes enough to depopulate it in a short time. Pikes four or five feet long are not rare in the great lakes of northern Europe and one of still larger size has been seen. In 1497 a pike was caught at Kaiser Lahtern near Mannheim, which was nearly 19 feet in length weighing 350 pounds. This giant was remarkable for its great age as for its size, for there was found upon it a gilt copper ring bearing this inscription. I am the first fish that was thrown into this pond by the hands of Frederick II, October 5th, 1230. It was consequently at least 267 years old. The growth of these fishes is very rapid. The first year they are often 10 or 11 inches in length and in the second 15. The Sea Pike, Esox Bologna, also known as the Garfish, Spitfish, and Billfish belongs to this family. Exoces, or flying fishes as they say, as well as Dactylopterus are also commonly called. Exocetus belong to the same family as the pikes and are recognized at first sight by the excessive length of their prectoral fins, which are long enough to serve them as wings and sustain them for a few seconds in the air. They swim in shoals and are pursued by lesions of voracious fishes to escape from which they spring out of water, but they soon fall again because their wings only serve them as a parachute. And while on their aerial course they become the prey of seabirds, as well as of sharks and other fishes. The family of Sileroides differs from all other abdominal malicopter regions in the absence of true scales. The skin is naked or furnished with bony plates. The dorsal and pectoral fins have almost always a strong articulated spine for the first fin ray, and as in the next family, there is often one adipose fin posteriorly and the mouth also has some peculiarities of structure. Most of these fishes belong to the tribe of Siluris, which is recognized by the naked skin by the mouth cleft at the end of the muzzle, and by a strong spine that, in general, constitutes the first ray of the pectoral fin, which is articulated with the shoulder and so arranged that it can be approximated to the body or raised perpendicularly to it and thus used as a dangerous weapon. The Siluri, properly so called, have a small fin on the four part of the back sustained by rays. One species of this genus, the only one in France is the largest freshwater fish of Europe. Its length ordinarily exceeds 6 feet and its weight is often 300 pounds. The catfish belongs to the tribe. The Malapteruri differ but little from the Siluri from which they are distinguished by the absence of a rayed fin on the back and by some other characters. The famous Siluris electricus of the Nile is the only species belonging to this division. Like the torpedo and gymnatus, it possesses the power of giving strong electric shocks. It appears that the seat of this faculty has a peculiar tissue, situate between the muscles and the skin, and having the appearance of a fatty cellular structure. This fish, which inhabits the Senegal as well as the Nile, is 18 or 20 inches in length. The Arabs call it rush, which signifies thunder. The family of Salmonides, of which the Salmons are the type, are characterized by a scaly body and a first dorsal fin with soft rays followed by a second which is small in adipose, that is, formed of a fold of skin filled with fat and without rays. The most interesting genus of this family is that of the Salmons, Salmo, which have the mouth more completely armed with teeth than any other fish. They are naturally voracious and ascend very far up rivers to deposit their eggs. Their body is almost always spotted and their flesh is much esteemed. The common Salmon, Salmo Salar, is the largest species of the genus. Its flesh is red, its body elongated and flattened laterally, and it often attains 6 feet in length. It is found in great numbers in all Arctic seas, whence it ascends rivers and large shoals every spring. It swims with great rapidity and can clear at a leap obstacles in its passage 12 or 15 feet in height. When they fall in with a cave or some other place favorable for spawning, they deposit their eggs in a hole in the sand and then permit themselves to be carried by the current to the sea, where they go to acquire strength to return again the following year. Young Salmons are therefore born in the rivers, but their growth is rapid, and when they attain to the sea like the adults. The Salmon fishery in many countries forms a very important branch of industry. In Norway as many as 300 of these fishes have been caught at a single cast of the net and in the river Tweed as many as 700. The time selected for catching them is when they ascend rivers to spawn for after they have deposited their eggs and are on their way to the sea, they are lean and their flesh is of little value. In general, this fishery is conducted with nets stretched across the river and so arranged that the Salmons are caught but sometimes in Scotland for example they are taken with a spear or harpoon. They are also caught with a hook in line. The salmon trout Salmo Truta, like the salmon has reddish flesh and the caudal fin crescent shaped, but it has on all the under parts of the body a great number of black spots oscillate or in form of an X. It sometimes weighs 8 or 10 pounds. The common trout Salmo Fario has the caudal fin but little notched and its flesh is white. It is also distinguished by the brown spots on the back and red spots surrounded by a bright circle on the flanks which are on a ground, the shade of which varies from white and golden yellow to a deep brown. It is commonly from 12 to 15 inches in length weighing about a pound but is sometimes met with of larger size. It inhabits rivers in the northern parts of Europe and the United States. Many other river trouts are known which are chiefly found in lakes and mountain streams and which vary in their size and colors in each locality. Some naturalists regard them as different species and look upon them as simple varieties resulting from age, food, and the quality of the waters in which they dwell. The smelts, osmaris, also belong to the family of Salmonides. They differ from the proceeding in the almost total absence of teeth on the vomar in the number of the Brachios tegus rays which is 8 in place of 10 and in the absence of spots on the body. They are caught in the sea at the mouths of large rivers. Their flesh is excellent. The common smelt, osmaris eperlanus is small. It is ornamented at the most dazzling, silvery, and light green tents. The skin is so exceedingly thin that under the microscope, the blood may be seen circulating in the cutaneous vessels. The graylings, thymalis have jaws like the trout, but the mouth is slightly cleft and the teeth are very fine. They have the habits of the trout and their flesh is equally esteemed. The common grayling, salmothymalis is striped blackish longitudinally. It attains a size of 18 inches and in the spring ascends several rivers of France and Italy. It is especially met with in the pure limpid waters of the mountains of America and Switzerland. The family of salmonides comprises a great number of other genera. The family of clupii has no adipose fin like the preceding. The upper jaw is formed as in the trouts in the middle by intermaxillary bones without pedicles and on the sides by the maxillary bones. The body of these fishes is always scaly and most of them ascend rivers. The most important tribe of this family is that of the herrings characterized by narrow, short, intermaxillary bones and by the inferior edge of the body being compressed, the scales of which are so arranged as to form notches like the teeth of a saw. These fishes are remarkable for the fineness and great number of their bones as well as for the peculiarities of their brankule apparatus. Herrings, properly so called clupia, have a moderate sized mouth without a notch in front. The common herring, clupia herringis is ordinarily 8 or 9 inches in length. The head small and compressed, the mouth slightly cleft, the lower jaw longer than the upper, the inferior edge of the body slightly careenate, the scales large and slightly adherent. The back blueish and the belly silvery. It inhabits the northern seas and arrives every year in innumerable legions upon different parts of the coast of Europe, Asia and America, but does not go very far south of the 40th degree of north latitude. Some naturalists suppose that all herrings periodically retire beneath the ice of the polar seas and set out from this common retreat in an immense column, which, dividing, spreads along almost all the coast north of the parallel above named, but this distant emigration and this common rendezvous in the arctic regions are far from being demonstrated and there is reason to believe that such is not the case. In the months of April and May herrings begin to appear in the waters of the Shetland Islands and towards the end of June or in July they arrive in incalculable numbers forming vast and dense shoals which sometimes extend over the surface of the sea for several leagues and hundreds of feet in thickness. In September they arrive on the coast of Great Britain. From that region they cross the Atlantic in a southwestern direction and make their appearance on the coast of Georgia about the last of January. Detachments then begin to move eastward and by the end of April the whole American seaboard is lined with them. The herring fishery is one of great importance. It occupies every year entire fleets and formerly it was carried on with still greater activity. About the middle of the 17th century the fishery was employed not less than 2,000 vessels and it is estimated that 800,000 persons in the two provinces of Holland and West Friesland derive their living from this branch of industry alone. The Norwegians, the Americans, the Scotch, the English, and even the French embarked in this fishery in considerable numbers and though its importance is now considerably lessened it is still a great source of wealth to the people bordering the northern seas. This fishery is ordinarily conducted with nets five or six hundred fathoms which is loaded with lead while the upper edge is made to float on the surface by means of buoys. The meshes are just large enough to receive the head of a herring as far as the gills but not allow the pectoral fins to pass. The fish, in endeavoring to overcome the obstacle that this great vertical partition opposes to its passage, is thus meshed. And not being able to advance or recede owing to the gills and fins he remains a prisoner until the fishermen draw the net on board. This is termed a gill net. The number of herrings taken in this way is sometimes that the net bursts under their weight. Generally this fishery is carried on at some distance from the shore and for this reason the herrings are salted on board. It is a prejudice to suppose that the herrings caught on our own coasts are inferior to those that fall into foreign nets. The sardine, clupia sardina, is a small species of herring celebrated for the great delicacy of its flesh and inhabits the Atlantic, the Baltic, and the Mediterranean. During winter it keeps in the depths of the sea but about the month of June it draws near the shore in immense shoals. As many as forty and even fifty thousand have been caught at a single cast of the net. Sardines are caught in the same way as herrings but the meshes of the net are smaller and the fishermen to attract the fish from time to time throw into the sea a peculiar bait which is prepared from codfish eggs. From the mouth of the Loire to the extremity of Brittany this fish abounds every summer and gives rise to productive fisheries along the coast there are a great number of establishments for the preparation and preservation of sardines. There are many other species of herring among the Piltred which does not differ much from the sardine except that it is larger. The Sprat which is smaller than the herring is also salted or pickled and the Whitebait, a very small fish of the most beautiful silver color with a black spot on the end of the muzzle. Shads, Alosa are distinguished from herrings properly so called by a notch in the middle of the upper jaw. The Common Shad, Alosa vulgaris which attains three feet in length and has no visible teeth, inhabits the sea and in the spring ascends rivers in numerous shoals. At this period their flesh is excellent but when the fish is caught at sea it is dry and possesses an unpleasant taste. The Alewife Clupia vernalis holds a place between the Shad and the herring possessing the general characteristics of both. Its habits bear a striking resemblance to those two fishes. It ascends rivers to deposit its spawn and afterwards retires to the ocean. It is found chiefly in the rivers of New England. The Anchoves and Growlis also belong to this family but they differ from the herrings in the mouth which is cleft far behind the eyes in their gills which are more open and in some other characteristics. The Common Anchove in Growlis and Crassicolis is three or four inches long. The back is brown and the flanks and belly silvery. It is found in the Mediterranean as well as on the western coasts of France and Spain in almost all parts of the North Atlantic Ocean and in the Baltic Sea. At a certain period of the year which varies in different localities it leaves the high sea and approaches the coast to spawn when it becomes the object of an important fishery. To catch it, the French fishermen provide themselves with nets which are about 200 feet in length and 25 or 30 in breadth and assemble four boats, one of which carries the net and the other's furnaces in which they make a bright fire. This fishery is carried on in dark nights from April to July. They station themselves about five miles from the coast and when the Anchoves attracted by the light are assembled in large numbers around a boat thus illuminated, the net is cast into the water and laid out so as to surround the assembled fishes. This done, the fire is suddenly extinguished and the Anchoves alarmed and seeking to escape are taken in the net. They are preserved with salt after removing the head and intestines. The family of Cloupier embraces a great number of other genera, many of which possess remarkable peculiarities but our limits will not permit us to describe them. End of Lesson 7 Recording by Lauren Hough Lesson 8 of the elements of herpetology and nectheology. This is a LibriVox recording. All LibriVox recordings are in the public domain. For more information or to volunteer, please visit LibriVox.org Recording by Lauren Hough Elements of herpetology and nectheology by William Rueschenberger Lesson 8 Order of Subbrakin Malicopter Regions Family of Godoidies Cods, Common Cod Cod Fishery Whiting, Hake, Ling Family of Pleuronectes Organization Place, Turbot, Sol Family of Discobalai Family of Echinias Remora Order of Apotus Malicopter Regions Eels, Common Eel Sea Eel, Gymnatis Electricus Order of Lofobrancheans Organization, Hippocampus Order of Plectonathae Organization, Diadon, Trunkfish Order of Malicopter Regii Subbrakiatae This order is distinguished from other Malicopter Regions by the situation of the ventral fins which are placed beneath the pectorals the pelvis being suspended immediately from the bones of the shoulder The Subbrakin Malicopter Regions constitute four families namely Godoidies, Pleuronectes Discobalai and Echinias The family of Godoidies is composed of Subbrakin Malicopter Regions in which the body is a little compressed and symmetrical in which the ventral fins are sharpened to a point and attached under the throat They are covered with soft small scales Most of them live in cold or temperate seas and they afford to man an abundance of good and wholesome food In this family are placed the genera of cod, whiting, ling, etc The Cods, Gattis are distinguished by the existence of three dorsal and two anal fins and a cirrus at the end of the muzzle or snout The most important species of this genus is the cod properly so called Gattis marua a fish two or three feet long with a gray back spotted yellowish and a white belly Cods are found in greatest abundance in the ocean between the 40th and 60th degrees of north latitude On the coasts of Norway in the neighborhood of Iceland and especially in the waters of Newfoundland they are found in incalculable numbers During winter they retire to the depths of the sea but in the warm season the necessity of casting their spawn and of providing for their subsistence causes them to approach the shore and fathomable waters In some localities the cod fishery is conducted with sains four or five hundred feet in length but generally they are caught with a hook in line baited with herring, the gills of codfish, etc A skillful fisherman may catch in this way four hundred cod fishes in a day The fish is prepared in different ways for preservation when simply salted it is known in commerce as green cod when dried without being salted it is stock fish and when salted and dried in the sun it is called dry cod The tongues salted or pickled with the swimming bladders are much esteemed and known under the title of tongues and sounds The sound or swimming bladder of the codfish if rightly prepared supplies an icing glass equal to the best Russian and applicable to all the uses for which the imported is employed The liver yields a large quantity of pure limpid oil, cod liver oil which in many respects and for most purposes is superior to the commonly used fish oil Catching and preparing codfish are very important branches of maritime industry About 12,000 French and a very much larger number of English and American fishermen are yearly engaged in this business The whitings, merlongus have the same number of fins as the cod but no sear eye The common whiting, gattus merlangus which is about a foot long, silvery beneath reddish gray or olive above may be recognized by the upper jaw being longer than the lower It inhabits European seas with the lightness of its delicate flesh On the coast of Brittany it is salted and dried like the cod The hakes, merlucius have no sear eye and differ from the cods in the number of their fins They have but two dorsal fins and one posterior to the anus The common hake, gattus merlucius is from one to two feet in length and sometimes much longer The back is brown gray The anterior dorsal fin pointed lower jaw longest It is usually found in pursuit of mackerel shoals When salted and dried it receives in the north the name of stockfish which is also applied to the cod The lings, lota have a greater or less number of sear eye and the same fins as the hakes They are almost as numerous as the cod in the northern seas The common ling differs from other gadoides in the almost cylindrical form of its body in its depressed head and habits It is the only fish of this family that ascends rivers into fresh water The family of pleuronectes comprises what are vulgarly called the flat fishes These animals have the body very much compressed laterally and very much elevated vertically but what especially distinguishes them is a want of symmetry in the head a character which is not observed in any other vertebrate animal Both eyes are placed on the same side which is always uppermost when the animal swims and is always deeply colored while the opposite side is always whitish The two sides of the mouth are unequal They are rare to find both pectoral fins perfectly alike The dorsal fin extends along the whole back The anal fin occupies the lower part of the body and the ventral seem to be continuous with it in front as they are almost united one to the other They want the swimming bladder swim on the side and seldom quit the bottom The principal genera of this family are the place, the turbot, and the soul The place, platessa have in each jaw a row of cutting and obtuse teeth Most generally the pharyngeal bones are furnished with teeth like pebbles The dorsal fin extends as far forward as a point above the upper eye leaving a naked interval between it and the caudal fin Their form is rhomboidal and most frequently their eyes are on the right side The commonplace platessa platessa is easily recognized by six or seven tubercles forming a straight line on the right side of the head between the eyes and by the paleo spots which relieve the brown on the same side of the body it is three times as long as it is high and its scales are thin and soft Its flesh is very tender and much esteemed Its weight sometimes reaches 16 pounds It is common on the coasts of France and abounds on those of Holland The flounder platessa fleasus resembles the commonplace but only has small granules between the eyes and has a small rough button at the base of each ray of the dorsal and atlefin It inhabits our coast and ascends rivers In many individuals the eyes are on the left instead of the right side of the head The lamandi or dab has a projecting line between the eyes and a body which is comparatively higher than it is long Its scales are rougher than in any of the preceding species from which circumstance it has derived its name from lima, a file The teeth are straighter and the side upon which the eyes are placed is light brown with some faded brown and whitish spots The halibut, hippoglossus vulgaris or platessa hippoglossus has the form and fins of a platessa but the jaws and pharynx are armed with teeth which are most commonly strong and pointed The eyes are on the right side It is a voracious fish and is found in the northern seas and our own coast It is taken with a line and sometimes weighs 500 pounds The turbot, platessa maximus has a rhomboidal body almost as high as it is long and studded on the brown side with small tubercles The eyes are close together and there is a projecting crest between them It is probably the most valuable of the flat fishes and accepting the halibut grows larger than any of the others It is highly prized in England It is also met with on our own coast Souls, solia have an oblong body a round projecting snout the dorsal extending from the mouth to the anal fin and the mouth distorted and armed with teeth on one side only The common soul, platessa solia or solia vulgaris is olive brown on the right side and grayish on the left It is found on our own coast chiefly at the mouths of rivers The family of discobalai is composed of a small number of subbrakean malicopter regions which have the ventral fins united in form of a disc It includes two genera in which are placed the lumpfish and lumpsucker The family of echinias formed of a single genus is remarkable among all fishes for a flattened disc which covers the head It is composed of a certain number of movable transverse cartilaginous plates standing obliquely backwards by the assistance of which the animal is attached itself to different bodies to which it applies the singular instrument By this means, it often attaches itself to rocks, to vessels and to other fishes, particularly to the shark A species which lives in the Mediterranean and the Atlantic has been long celebrated under the name of remora, or sucking fish and its history is loaded with fable It was pretended that this fish lived by a species of suction which it exerted by means of the disc above mentioned and the power of arresting the fastest sailing vessel which of course was attributed to it A species similar to the proceeding is very common in the waters of the Isle of France and it appears that on the coast of Graffararia it is employed in fishing Setting it off in pursuit of fishes and drawing it in by a line attached to the tail as soon as it has fixed itself to its prey Order of Malicopter Regii apoda All the fishes of this order have an elongated form a thick, soft, and but slightly scaly skin, but their chief characteristic is their want of ventral fins They form a single natural family anguiliformes which is composed of the tribe of eels genitus, etc, etc Fishes of the tribe of anguiliformes have a long, slender body and the scales as it were encrusted in a thick, fat skin The operculum is small, surrounded by the brachioscegous rays in form of a circle which are enveloped in the skin and open very far back by a hole or sort of tube an arrangement which affords better protection to the gills and enables these fishes to remain some time out of water without perishing Eels, myrina are characterized by having pectoral fins and the openings of the gills beneath them Those which have the dorsal and codle fins prolonged around the end of the tail so as to form a pointed codle fin are designated under the name of eels properly so called and are again subdivided into common eels and conger eels according as the dorsal fin commences far from or near to the pectoral fins Common eels, anguila are too well known to require description their color varies according to age and as it appears according to the quality of the water in which they dwell those that inhabit limpid waters have a greenish back striped brown and a white or silvery belly while those that are caught in the mud are ordinarily blackish brown above and yellowish beneath Eels are very voracious and extremely agile they swim equally well backward and forward and their skin is so slippery that it is difficult to hold them during a great part of their life they inhabit fresh water and frequent ponds and seas as well as rivers by day they almost always keep buried in the mud or like concealed in holes they excavate near the shore these holes are sometimes very extensive and lodge a great number of eels but in general their diameter is small and they open externally at both ends which enables the animal to escape more readily when threatened by danger when the season is very warm and the stagnant waters of the pools begin to putrify the eels leave the bottom and conceal themselves in the urbage of the shore in a more favorable locality they can in fact crawl on the ground like serpents and remain a considerable time in the air without perishing ordinarily they make these singular journeys during the night and when it is extremely dry they bury themselves in the mud and continue there until the water returns the length of time they can remain there without perishing is surprising these fishes have been known to remain for months or even years in the mud of dried up pools or in holes destitute of water and nevertheless regain their activity this is not the only circumstance under which these fishes display their remarkable tenacity of life they may be deprived of their skin and their viscera and be cut in pieces without depriving the trunk of their body of the power of yet moving for some time in early life they inhabit the sea and in the spring the young eels ascend rivers to dwell in fresh water which when full grown they abandon to deposit their eggs in the sea the name of conger eels is applied to eels that differ very little from common eels except that they are of large size and they always dwell in the sea or salt water murini properly so called murina are entirely without pectoral fins and their branqui open on each side by a small hole the most celebrated species is the murina helina which attains more than three feet in length and is marbled throughout with brown and yellowish it is widely spread over the Mediterranean and was very highly esteemed by the ancients the romans reared them in great numbers in their magnificent fish ponds decorated them with jewels and taught them to come at the sound of their masters voice hirius was the first to consecrate fish ponds exclusively to murini and he caused six thousand of these fishes to be served up in an entertainment given to caesar when he was named dictator the gemnitai which have the gills partially closed by a membrane but opening in front of the pectoral fins also belong to this order the gemnitai properly so called gemnitus have, like the other fishes of this division, a ventral fin which extends under the greater part of the body but they want the fins at the end of the tail without perceptible scales they inhabit the rivers of south america and one of them, the electric eel gemnitus electricus is celebrated on account of the violent electric shocks that has the power of communicating at will and in the direction it pleases this fish acquires five or six feet in length its body is elongated and of the same size throughout and its skin is imbued with a gluey matter it is very common in the small rivulets and lakes and met with here and there on the immense plains situate between the cordillera and banda oriental it is also found in the apure, orinoco meta, etc the electric shocks which it gives are sufficiently powerful to knock down men and horses and the gemnitus resorts to this means of defending itself against its enemies and to kill at a distance fishes upon which it feeds for water as well as metals transmits the benumbing shock of the singular animal in the same manner that the lightning rod conducts the electricity of the clouds from the atmosphere to the earth its first discharges of electricity are generally feeble but when it is irritated and agitated they become more and more powerful and are then terrible when it has thus given repeated shocks it becomes exhausted and requires a greater or less period of rest before it regains its power it is said that it employs this time in charging its electric organs and that the americans avail themselves of this circumstance to capture it without danger to catch the gemnotype they drive into the pools inhabited by these fishes wild horses which receiving the first shocks are soon benumbed and thrown down or even killed then they obtain the exhausted gemnotype with nets or a harpoon the electric apparatus of the gemnitus extends all along the back and tail and consists of four longitudinal fasciculi composed of a great number of membranous plates which are parallel and very close together and deranged almost horizontally and united by an infinity of other smaller lamellae placed vertically crosswise the little prismatic and transverse cells formed by the junction of these laminy are filled by a gelatinous matter the whole apparatus is supplied with very large nerves order of lofabranchi eye this order is distinguished by the branqui which in place of being pectinate that is having the form of comb teeth as is ordinarily the case are divided into small round tufts arranged in pairs along the branquil arches they are enclosed under a large aperculum which is attached on all sides by a membrane leaving only a small hole for the escape of water and in its thickness we find only vestiges of branquiostecus rays these fishes are also recognized by the male-like plates which cover the body and render it almost always angular they are generally small to this order belongs the hippocampus the body of which is laterally compressed and more elevated than the tail on curling up after death the head and trunk bear some resemblance to the head of a horse in miniature which is obtained for this little fish the common name of seahorse order of Plectonathae the fishes composing this group form the connecting link between the ordinary and cartilaginous fishes as much by the conformation of their jaws as by the tardy consolidation of their skeleton their chief distinctive character is that the maxillary is solidly fixed upon the side of the intermaxillary bone which alone forms the jaw and that the palatine arch articulates with the cranium in a manner which renders it immovable moreover their apercula and branquiostecus rays are concealed beneath a thick skin which leaves externally only a small branquil slit they have no true ventral fins and they have only vestiges of ribs this order comprises two families recognizable by the opening of their mouth namely the gemnodontes and the sclerodermae in the family of gemnodontes there are no apparent teeth but the jaws are furnished with a species of ivory beak internally divided into plates which represent the teeth it includes the diodon, the tetrodon the mole, etc the diodon has received this name because the jaws being undivided have each but a single piece while in the tetrodon they are divided in the middle by a suture so as to present the appearance of four teeth two above and two below these two genera fishes have the faculty of swelling themselves up like a balloon by swallowing air and thus distending a first very extensible stomach which occupies the whole length of the abdomen this peculiarity has obtained for them the common names of swellfish porcupinefish, balloonfish blower, etc and furnishes them with a means of defense for when the skin is distended the spines with which it is armed become everywhere erect and bristle the whole surface of the body and when they are thus swelled they turn over the belly coming uppermost and they float on the surface of the sea without the power of directing their course they are found in the tropical seas and on the North American coast the sunfishes are moles cephalus sometimes called moonfishes resemble the diodon in the arrangement of their jaws but their body which is compressed and of a strange shape has no spines nor is it susceptible of inflation and their tail is so short and so high vertically they appear like fishes having the posterior part cut off one species which sometimes attains more than 4 feet in length weighing over 300 pounds inhabits the coast of France the family of sclerodermae is easily distinguished by the conical or pyramidal snout prolonged from the eyes and terminated by a small mouth armed with a small number of distinct teeth the skin is generally rough or covered with hard scales some of them named ballisties have a compressed body covered by a scaly or granular skin but not osseous they have eight teeth generally trenchant arranged in a single row in each jaw and two dorsal fins they are found in great numbers in the torrid zone others called trunk fishes ostracion have in place of scales regular bony compartments are plates united into a kind of inflexible coat of mail which covers the head and body so that they can only move the tail the fins the mouth and a kind of small lip around the edge of their gills which pass through the holes in this queer ass each jaw is armed with 10 or 12 conical teeth they are found on the coast of the united states end of lesson 8 recording by lauren hoff