ICHTHYOLOGY. 



321 



tion- 

 Sharks. 



Classifica- we think it necessary to mention in the summary that our 

 restricted hraits compel us to resort to, are the organs of re- 

 production. In these fishes the secreting organs, or melts, 

 are of compact oval or oblong form, and their efferent 

 tubes communicate with the ureters, and terminate upon a 

 rudimental organ in the cloaca. The claspers are present 

 in the Chimttridxe as v\ell as Plagiostomi, as appendages to 

 the posterior edges of the anal fins, and have a fissure to- 

 wards their ends, leading to a blind subcutaneous sac, which 

 is well lubricated with mucus. In the Rays a glandular 

 body adds its secretions to this mucus. The ovaria are 

 smaller than those of osseous fishes, and the ova compara- 

 tively few in number. Some of the genera are viviparous, 

 others ovo-viviparous, and others again merely oviparous. 



SHARKS. 



The ScylliidjE or Dog-fishes, have the anal fin situated 

 either before or beneath or behind the second dorsal, and are 

 mostly spotted or coloured with lively tints. Their French 

 names are Roitsette or Rocher. The typical genus Sci/llium 

 has two representatives on the British coasts, Sc. caiiicula 

 and Sc. catuhts, both very common, and constantly taken by 

 the fishers with bait at all the fishing stations round the 

 coast, but more plentiful among the Orkney Islands than 

 elsewhere. They are scarcely ever brought to market, but 

 the fishermen do not disdain to eat them. Their flesh is 

 remarkably white, but a little fibrous and dry. In the 

 Orkneys they are skinned, split up, cleaned, aud then 

 spread out on the rocks to dry for home consumption. The 

 skins are used for smoothing down cabinet work. There 

 is no reason why the fins of these and other Sharks, so ex- 

 tensively used in China for making gelatine soups, should 

 not be applied to the same purpose in this country, or dried 

 for exportation to the East. Both the British species 

 exist in the Mediterranean also. Six different species fre- 

 quent the seas that wa^h the Cape of Good Hope, and there 

 are at least two on the coasts of Japan and China. The 

 only described species of Prisiiurus is a Mediterranean one, 

 but individuals sometimes stray northwards to the British 

 Channel ; and one procured by Mr Couch, at Polperro in 

 Cornwall, is figured by Mr Yarrell under the appellation of 

 the " Black-mouthed Dog-fish." It is known at Madeira 

 as the " Leitao de Mar," but is considered to be extremely 

 rare. The handsome Hemiscyllia are Australian, and the 

 Chiloscyllia belong to the Indian Archipelago and Poly- 

 nesia. The curious bearded Crossorhi/ntis fi-equents the 

 seas of Japan as well as those of Australia, where it was 

 first discovered, having thus a range extending over many 

 parallels of latitude. Ginglymosloma has a representative 

 in the Indian Ocean and Red Sea, and another on the coast 

 of Cayenne, and Stegostoma belongs wholly to the Eastern 

 seas. Stegosloma fasciata is one of the most beautiful of 

 the order, and has been observed of the length of fourteen 

 or fifteen feet, with a large and blunt head, and tapering 

 body. A few years ago one of them followed for several 

 hours a Liverpool East Indiaman off Madagascar. It was 

 elegantly transversely banded with alternate whitish and 

 dark brown or blackish fasciae ; and was further variegated 

 by ocellated spots or rings on various parts of its body, 

 which seemed to be about fourteen feet long. Its head ap- 

 peared to be four and a half feet across, but the thickest 

 part of its body did not seem more than two feet in diameter. 

 It was accompanied by several Pilot-fish, which often swam 

 before and returned towards it. Several attempts were 

 made to catch it with large baits of fresh meat, but it never 

 ventured to seize one of them. The lower jaw was dis- 

 tinctly visible whenever it opened its mouth, into which the 

 accompanying fishes seemed to the spectators to enter and 

 to leave at pleasure. The Scylliidte generally have the 

 parts about the nose and mouth more divided into cutaneous 



VOL. XII. 



lobes and barbels, evidently as organs of touch, and in Classifica- 

 harmony with their habits as Ground Sharks. For they •ion- 

 require some guide to keep them from grazing against the ^''*''''''- 

 bottom in their rapid pursuit of their prey. ^"^v""^ 



Under the appellation of true Squali {Squales propre- 

 merit dits), Cuvier comprehended all the remaining Sharks 

 except Zygeena and Squatina, which he characterized as 

 distinct genera. His genus Squalus, therefore, included the 

 Carcharid(e, GaleidiB, Lamnidce, Alopeciidm, Rhinodontida, 

 and ScymnidcB of Muller. In Mr Owen's table, the Spina- 

 cid(B, Lamnidte, Alopeciida, and Scymnidce are separated 

 from the Squali of Cuvier, and the remainder of that gro\ip 

 are denominated, after ^VuWer, Nyctilantes,v/\\\c\\ are chiefly, 

 therefore, CarcharidcB and Galeidm. The presence of a nic- 

 titating membrane to the eye is accompanied with a greater 

 induration of the skeleton. This membrane, as it exists in 

 Galeiis, is superadded to a well developed circular palpebral 

 fold of the skin. A su|)erficial membrane or conjunctiva is 

 reflected from the circular eyelid over the third eyelid, which 

 is placed on the nasal side of the orbit. The third or nicti- 

 tating eyelid is raised, and the upper part of the circular one 

 depressed at the same time by muscular action when the 

 fish wishes to close the eye. In our arrangement of the ge- 

 nera, we have generally followed the Plagiostomen of Muller 

 and Henle, whose generic characters we have abridged, 

 not having access at present to Midler's later works. 



The Carcharid^ are armed with teeth which, by their 

 arrangement in a linear series, make a sharp saw, each tooth 

 in the majority of species being also serrated on the edge. 

 The common form of the upper teeth is that of the tip of a 

 lancet, frequently oblique, one shoulder of the lancet being 

 more curved than the other. The teeth of the lower jaw 

 are either similar to the upper ones, or have narrower cusps, 

 according to the species. Each jaw supports several rows 

 of teeth, the anterior row on the edge of the jaw being 

 erected for use, and the posterior ones lying flat in the hollow 

 of the cartilage, and coming forward in succession as they 

 are required by the decay and loss of the front ones. No 

 animal possesses a more perfect incisorial apparatus than 

 these massive but powerfully active tyrants of the deep. 

 They have been known to divide the body of a man in two 

 at one bite, as if by the sweep of a sword, and we once had 

 an opportunity of observing how clean a cut a Shark's jaws 

 were capable of making. A piece of salt-beef weighing 

 about 14 lbs. was hanging over a ship's stern, suspended by 

 a strong cord in a net of sinnet. Sinnet is the sea term for 

 a flat plait of rope yarns, more pliable but equally strong with 

 rope containing the same quantity of material, and, from its 

 looseness of texture, capable of stretching more, and less 

 easily cut. In this instance, the sinnet forming the meshes 

 of the net was of the wideness of two fingers' breadth. The 

 beef just dipped below the surface of the water or rose above 

 it, as the ship's stern rose and fell with the gentle swell of a 

 tropical sea. Suddenly a Shark came up from tlie deep, and 

 before the spectators could raise the beef on which a hungry 

 party hoped to make a dinner, the monster turned his mouth 

 gently upwards, and, without plunge or struggle, carried off 

 the beef and half the net to the depths into which he imme- 

 diately descended. The sinnet was cut evenly across as if 

 with a razor. Had it been torn by the mere weight of the 

 fish, the rope yarns would have hung out of unequal lengths, 

 and the seamen considered that on exposure to a simple 

 strain, the rope by which the net was suspended would have 

 broken long before the net itself gave way. A Shark killed 

 near Marseilles, is alleged to have had the entire body of a 

 man and several fish in its stomach ; and one captured off 

 Santa Margaretta is said to have contained the carcass of a 

 horse. Its weight was 1500 pounds. The cartilaginous 

 jaws of Sharks shrink at least a third in drying, and cannot, 

 as they lose their moisture, be kept at full stretch without 

 tearing, yet specimens are not very rare in museums which 



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