126 



SUB-CLASS C HONDROPTERYGII. CARTILAGINOUS FISHES. 



Shark. 



horn, anil answering to teeth ; tongue beset with two rows of very 

 small teeth, and extensile ; on each side of the head seven branchial 

 nurtures, with a peculiar canal commencing immediately below the gullet 

 connected with them ; two dorsal fins distinct ; no anal fin ; tail fin con- 

 sisting of a longitudinal fold of skin above and below supported on very 

 delicate, indistinct rays. 



2. GASTROBRANCHCS (Gr. yam-rip, tetty, and /3payx ia > a 9)- Open- 

 ings of the gills under the belly ; no fins except the caudal. 



PLAGIOSTOMATA, CYCLOSTOMATA. DESCRIPTION OF THE SPECIES. 



SQUALUS Shark. The Sharks are extremely ferocious, and of pro- 

 verbially gluttonous habits. They do not swim with great speed, their 

 progress being retarded in some degree by the position of their mouth requiring 



them to turn on 

 one side when 

 about to seize 

 their prey. They 

 were formerly 

 said to be pos- 

 sessed of a fine 

 scent, but Quoy 



and Gaimard have proved that this is not the case, and that rather their 

 vision is acute. They appear to be found in all seas, mostly upon the 

 coast, but between the tropics are often met with on the high sea. Their 

 habits are generally solitary, except when hunger draws them into bays or 

 other inlets, when they are seen in swarms. Their flesh is coarse and . 

 tasteless, but rarely eaten except from the tail. The liver is very greasy, 

 and large quantities of oil are obtained from it. The skin rough, and from 

 some species it is used in the manufacture of a sort of shagreen. 



The White Shark (S. Carcharias) measures from twenty-five to thirty 

 feet in length ; the body spindle-shaped, and covered with hard granular 



skin ; head large, muzzle 

 largely furnished with pores 

 which exude a glairy se- 

 cretion ; mouth large, wide, 

 and semicircular ; upper 

 jaw armed with six, and 

 the lower with four rows of 

 teeth, amounting to four or 

 Head of Shark. s ; x hundred ; tongue short, 



thick, and rough, as is also the palate ; eyes round, the irides pearly-white, 

 and the pupils blackish ; upper parts of the body brown, under parts 

 white, and two rows of black pores upon the sides. 



SQUATISA Angel-fish. The Angel-fish (S. Angelus) is from .five to 

 seven or eight feet long, and up to one hundred pounds in weight ; upper 

 .surface dark mottled-chocolate, under parts dirty white. From the sup- 

 posed resemblance of the pectoral fins to wings, the animal has acquired its 

 name of Angel-fish. It is not uncommon upon the British coast, where it 

 is known as the Angel, Monk, or Fiddle fish, from the size of its pectoral 

 fins, from the head being sunk within the pectoral as within a cowl, or its 

 siiajx! resembling a fiddle. It produces in the spring and autumn seven or 

 eight young ones. It is a very fierce and voracious animal. 



TORPEDO Cramp-fish. The space between the pec- 

 torals and the head is filled by an electric apparatus, amply 

 supplied with nerves, and consisting of numerous cells like 

 honeycombs, in the intervals of which a mucous fluid is 

 contained. The shocks are not so benumbing as those 

 by the Gymnotus. This remarkable numbing property 

 was known to the ancients. 



The Torpedos are predaceous and live on sandy places, 

 where they bury themselves at a slight distance below tin- 

 surface by a quick flapping of their fins, which throws 

 Torpedo. the sand over them. They will live for twenty-four hours 

 out of water, but not longer. 



The Spotted or Eyed Cramp-fish (T. Narke) occasionally measures about 

 twenty inches in length ; eyes black ; upper surface reddish-yellow, marked 

 with five large roundish spots azure blue changing to grey, eacli surrounded 

 with a broad brown circle, and arranged in a pentagonal form, accompanied 

 with numerous whitish spots ; under surface whitish ; spiracles dentated. 



RAJA. The upper surface of the body, in all the individuals of this 

 genus, is more or less armed with spines, and in some species a distinct 

 row passes along the ridge of the back to the tip of the tail. 



The Rough or Thornback Ray (R. Clavata) is more than two feet in 



length; muzzle pointed ; skin shagreened ; up(ier 



parts brown sprinkled with whitish spots, but 



sometimes white with black spots. They are 



common on the British sands, feed on flat-fish, 



are very fond of Herrings and Sand-eels, and 



sometimes eat crustaceous animals. They bring 



forth their young in July and August, and before 



these are old enough to breed they are commonly 



called Maids. 



Other genera of this family : Rhina, Round-muzzle ; Rhinobatus, /Sharp- 

 snout; Selache, Basking-Shark ; Scyllion, Dog-fish; Scymnus, a kind of 



Shark; Spinox, Prickly-Shark ; Trygon, Stingray ; Zygcena, Hammer-head. 



Mouth of Lamprey. 



PETROMYZON Lamprey. The Lampreys are remarkably charaet. n>. .1 

 by the canal which leads from the cavity of the mouth beneath the gullet 

 to their bag-like gills, and which corresponds to the windpipe < >t 

 The mouth itself has much resemblance to a shallow 

 cup, which the animal is capable of exhausting so as 

 to attach itself firmly to any substance, whilst the 

 horny teeth contained in its surface either hold it 

 more tightly, or, if soft, break it into small pieces so 

 that it may more readily pass the narrow aperture of 

 the gullet; by this powerful organ they attach them- 

 selves to large fish, penetrate their skin, and devour 

 them. They are found in most of the European rivers. 



The Sea Lamprey (P. Maximus) is about two or three feet in length ; 

 the head is of a greenish-brown colour ; the eyes round with a black pupil 

 and golden iris ; the 

 back and sides are 

 marbled with green 



and blue, and the Lamprey, 



belly white; the dor- 

 sal fins are orange marbled with brown, and the caudal bluish. Tin 

 sea-fish, but, like the Salmon, it leaves the salt water early in the spring, 

 and enters the mouths of rivers, probably for the purpose of spawning. 

 On its lirst arrival, and during March, April, and May, its flesh is firm and 

 highly flavoured, but after that time becomes flabby and unsavoury. It. 

 sometimes weighs as much as three pounds, and occasionally tour or six. 



GASTROBIUNCHUS. In this genus the spaces between the branchial 

 arches open on each side into a single canal, which terminates beneath the 

 heart; mouth circular, surrounded with eight little beards, and hav 

 hole pierced through its upper edge; a single tooth is found on the top .4 

 the maxillary ray, but those of the tongue are strong, and disposed in tun 

 lateral rows; body cylindrical. Two species; one found in the Nort; 

 the Myxme (G. Caecus), which often annoys the Turl><>t fUlicrns, Ky 

 attacking the fish that are hooked, and leaving nothing but the skin and 

 bones. The other G. Dombey, on the Guinea coast, and considered h\ 

 Schneider as merely a variety of the former. 



PHISTIS Saw-fish. This genus is of the family Selacia, and uas 

 formerly included in the genus Squali, till Linna-us removed it in the ve.u 

 1794, and placed it as it now stands. Th, 



