956 



PISCES. 



breeding season, alone occupies and guides 

 them, is to assuage the internal feeling of 

 hunger, to devour almost all that they can. To 

 pursue a prey or to escape from a pursuer 

 makes the occupation of their life ; it is this 

 which determines their choice of the different 

 situations which they inhabit; it is the prin- 

 cipal cause of the variety of their forms and of 

 the special instincts or artifices which nature 

 has granted to some of the species." 



" Vicissitudes of temperature affect them 

 little, not only because these are less in the ele- 

 ment which they inhabit than in our atmosphere, 

 but because their bodies taking the surrounding 

 temperature the contrast of external cold and 

 internal heat scarcely exists in their case. Thus 

 the seasons are not so exclusively the regulators 

 of their migration and propagation as amongst 

 Quadrupeds or more especially Birds. Many 

 Fishes spawn in winter; it is towards autumn 

 that herrings come out of the north to shed 

 upon our coast their spawn and milt. It is in 

 the north that the most astonishing fecundity is 

 witnessed, if not in variety of species, at least 

 in individuals ; and in no other seas do we find 

 anything approaching to the countless myriads 

 of herrings and cod which attract whole fleets 

 to the northern fisheries." 



" The loves of Fishes are cold as themselves ; 

 they only indicate individual need. Scarcely 

 is it permitted to a few species that the two 

 sexes should pair and enjoy pleasure together; 

 in the rest the males pursue the eggs rather 

 than seek the females ; they are reduced to 

 impregnate eggs the mother of which is un- 

 known, and whose produce they will never see. 

 The pleasures of maternity are equally un- 

 known to most species ; a small number only 

 carry their eggs with them for a short time ; 

 with few exceptions Fishes have no nest to build 

 and no young to nourish : in a word, even to 

 the last details, their economy contrasts diame- 

 trically with that of Birds." 



In no class of the animal kingdom do we 

 find such diversity of form as in that of Fishes. 

 Some amongst them are perfectly spherical, 

 as the Dioduns. Others are discoidal, or flat 

 and circular, and this shape may be produced 

 by two very different conditions, resulting either 

 from an excessive narrowing or inordinate ex- 

 pansion of the two sides of the body. In the 

 first case it is compressed and much elevated, 

 as in Vomer and Orthagoriscus, while in the 

 second case it is much depressed, flattened, and 

 very broad, as in the Skates. Other species 

 are oval, more or less elongated and slightly 

 compressed laterally, such as Carp, Trout, &c., 

 which is the most ordinary shape. Neverthe- 

 less when these become extended longitudi- 

 nally (as in the Pikes for example), we are 

 insensibly conducted by all intermediate grada- 

 tions of form to the cylindrical Eels, or to com- 

 pressed and riband-shaped Fishes, such as 

 Cepola. Perhaps the most remaikably shaped 

 Fishes are those whose bodies are bounded by 

 nearly flat surfaces, and which circumscribe 

 angular figures, such as triangles, squares, pen- 

 tagons, hexagons, Stc.jf Ostracion, Syngnathus.) 

 There are even certain genera in which the two 



sides are not symmetrical, one being flattened 

 and the other vaulted, and in these races even 

 the bones of the cranium are so disproportioned 

 that both eyes are turned to the same side of 

 the animal ( ' Pleuronectida). 



The following arrangement, being a modifi- 

 cation of the classification proposed by Cuvier, 

 will facilitate our investigations relative to the 

 anatomy of the numerous members of this 

 extensive class. 



PISCES. 

 DIVISION 1.- CHONDROPTERYGIL 



Skeleton cartilaginous, fins supported by 

 cartilaginous rays. 



ORDER I. Branchiae fixed. 



1st Family. PLAGIOSTOMATA. Squalus, 

 Zygasna, Squat ina, Pristis, Raia. 



OIIDER II. Branchiae free. 



1st Family. STURIONID^E. Accipenser, 

 Spatularia, Chimera. 



DIVISION ll.OSTEOPTERYGII. 



Skeleton composed of true bone. 



ORDER I. ACANTHOPTERYGII. 



The Fishes belonging to this division are at 

 once recognised by the stiff spines which con- 

 stitute the first fin-rays of the dorsal fin, or which 

 support the anterior fin of the back in case 

 there are two dorsals. In some cases the an- 

 terior dorsal fin is only represented by detached 

 spines. The first rays of the anal fin are like- 

 wise spinous as well as the first ray of the ven- 

 tral fin. This order, which comprises by far 

 the greater number of osseous Fishes, is divi- 

 sible into the following families. 



1st Family. PERCID^E. Perca, Labrax, 

 Lutes, Ceiit/vpomus, Grammistes, Aspro, Apo- 

 gon, Cheilodipterus, Pomatomus, Ambassis, 

 Lucio-Perca, Serranus, Plectropoma, Diacope, 

 Mesoprion, Accrina, Ri/plicus, Poli/prion, 

 Centropristis, Grmtes, Cirrhites, Chironemus, 

 Porno t is, Centrarchus, Priacanthus, Dales, 

 Tlierapon, Pelates, Helotes, Trichodon, Sillago, 

 Holocentrum, Myripristis, Beri/x, Trachichtys, 

 Trachinus, Percis, Pinguipes, Percophis, Urun- 

 oscopus, Polynemus, Sphymna, Paralepis, 

 Mullus. 



2nd Family. SctEROGENiD^hard cheeks). 

 Trigla, Prionotea, Pcristedion, Dacti/lopterus, 

 Cephalacanthes, Coitus, Hemitripterus, Hemi- 

 lepidotus, Platycephalus, Scorpozna, Pterois, 

 Blepsias, Apistes, Agriopes, Pelors, Synanceia, 

 Monucentris, Gusterosteus, Oreosoma. 



3d Family. SCIJENIDS. Sciana, JLques, 

 Htemulon, Pristipoma, Diagramma, Lobules, 

 Cheilodactyles, Scolopxides, Microptents, Am- 

 phiprion, Premnas, Pomacentres, Dascyllus, 

 Glyphisodon, Hcliases. 



4th Family. SPARID*. Sargus, Chryso- 

 phris, Pagrns, Pagellus, Dentex, Cantharus, 

 Boops, Oblada. 



5th Family. M^NID^E. Masna t Smarts, 

 Ctraio, Germs. 



6th Family. SQUAMMIPENNES. Cha'to- 



