242 FISHES. 



These fishes have both pectorals and ventrals : the latter are situated 

 behind the abdomen, and on each side of the anus. Their membra- 

 nous labyrinth is enclosed by the cartilaginous substance of the cra- 

 nium; the sac, which constitutes part of it, contains mere amylaceous 

 masses, and no stones. The pancreas resembles a conglomerated 

 gland, and is not divided into distinct tubes or caeca. The intestinal 

 canal is short in proportion, but a portion of it is provided internally 

 with a spiral lamina, which prolongs the delay of the ailments. 



Fecundation is performed by a real intromission of semen ; the 

 females have highly organized oviducts, which supply the place of a 

 matrix in those whose young are hatched within their body ; the 

 others produce ova, invested with a hard or horny shell, to the 

 formation of which a large gland that surrounds each oviduct 

 contributes. The males are recognised by certain appendages, 

 situated on the internal edge of the ventrals, which are very large, 

 and highly complicated, and Avhose use is not well understood. 



Squalus*, Lin. 



The Sharks form a first great genus distinguished by an elongated 

 body, a thick fleshy tail and moderate pectorals, so that the general 

 figure approaches that of ordinary fishes ; the branchial openings 

 correspond with the sides of the neck, and not with the under surface 

 of the body as we shall see is the case with the Rays ; the eyes also 

 are on the sides of the head. The snout is supported by three car- 

 tilaginous branches connected with the anterior part of the cranium, 

 and the rudiments of the maxillaries, intermaxillaries, and preman- 

 dibularies are evident in the skeleton. 



The shoulder bones are suspended in the fleshy part behind the 

 branchiae without articulating either with the cranium or spne. 

 Several are viviparous. The others produce ova invested with a 

 yellow and transparent horn, the angles of which are prolonged into 

 horny cords. The little branchial ribs are apparent, and there are 

 also small ones along the sides of the spine, which is completely 

 divided into vertebrae. The genus is very numerous and authorizes 

 various subdivisions!. We first separate the 



ScylliumJ, Cuv. 



Distinguished from other Squali by the short and obtuse snout, and 

 by the nostrils opening near the mouth, continued in a groove extending 

 to the edge of the lip, and more or less closed by one or two cutaneous 



* Squalus, the Latin name of a fish, employed by some authors ; the species, 

 however, is unknown. Artedi applied it to this genus. We also find Squalus for 

 Squalina. 



t The flesh of this genus is generally of a leathery texture, and is used as food 

 only by the neediest. 



X Scyllium, one of the Greek names of this fish. 



