SQUALUS.] PISCES (CARTILAG.) PLAGIOSTOMI. 505 



may be hereafter met with. The Basking Shark of Pennant is repre- 

 sented as a tame and inoffensive species, deriving its English name from 

 its habit of " lying as if to sun itself on the surface of the water." Its 

 food is supposed to consist entirely of marine plants, no remains of fish 

 having ever been discovered in the stomach. Pennant thinks that it 

 is migratory. 



(7. SPINAX, Cuv.) 

 194. S. Acanthias, Linn. (Picked Dog-Fish.) 



S. Acanthias, Linn. Syst. Nat. torn. i. p. 397. Block, Ichth. pi. 85. 

 Don. Brit. Pish. vol. iv. pi. 82. Turt. Brit. Faun. p. 114. 

 Blainv. Faun. Franq. p. 57. Cuv. Reg. An. torn. u. p. 392. 

 Galeus Acanthias sive Spinax, Will. Hist. Pise. p. 56. tab. B. 5. 

 f. 1. Spinax Acanthias, Flem. Brit. An. p. 166. Picked Dog- 

 Fish, Penn. Brit. Zool. vol. HI. p. 100. Picked Shark, Id. (Edit. 

 1812.) vol. in. p. 133. 



LENGTH. From three to three and a half, sometimes four, feet. 



DESCRIPT. (Form.) General form much resembling that of the S. 

 Mustelus: body moderately elongated: head depressed; snout long, 

 conical, obtuse at the extremity : nostrils beneath, more remote from the 

 mouth than in the S. Mustelus, partly covered by a minute cutaneous 

 flap: jaws bent: teeth in two rows, small, sharp, the edges cutting and 

 not denticulated, bending from the middle each way towards the corners 

 of the mouth, the points short and inclining backwards: eyes large, 

 oblong : temporal orifices large, round, placed higher than in the S. Mus- 

 telus : branchial openings five in number, small, a little decreasing in 

 size from the first to the last ; placed in a line with the base of the pec- 

 torals, the last opening being immediately in advance of those fins : skin 

 very rough when rubbed from tail to head, but nearly smooth in the 

 opposite direction : lateral line tolerably well-defined, straight : two dor- 

 sals; in form and situation much as in the S. Mustelus, but before each 

 a sharp strong spine ; the spine of the second stronger and longer than 

 that of the first : caudal unequally forked, the upper lobe projecting far 

 beyond the lower : no anal : pectorals broad, triangular, cut square be- 

 hind, reaching when laid back to a vertical line from the spine of the first 

 dorsal: ventrals a little behind the middle of the entire length, much 

 smaller than the pectorals, obliquely truncated. (Colours.) Of a uniform 

 reddish gray, or grayish brown above; whitish beneath. The young, 

 according to Bloch and Cuvier, are spotted with white. 



A common species on all parts of the British coast. Is very voracious, 

 preying on other fish. Ovo viviparous. 



(38.) S. Spinax, Linn. Syst. Nat. torn. i. p. 398. Stew, El. of 

 Nat. Hist, vol.i. p. 319. Blainv. Faun. Franc, p. 60. Nilss. 

 Prod. Ichth. Scand. p. 118. Acanthias Spinax, Iliss. Hist. Jat. 

 de 1'Eur. Merid. torn. HI. p. 132. 



This species is marked as British by Stewart, in both Editions of his 

 "Elements of Natural History," but on what authority he does not men- 

 tion. It is not noticed, that I am aware, by any other of our English 

 authors. Said to be distinguished from the last, which it closely resembles, 

 principally by the abdomen being nearly black, and the nostrils at the ex- 

 tremity of the snout. According to Nilsson, it is the smallest species in 

 the genus, not exceeding a length of sixteen inches. It is found in the 

 Northern seas, as well as in the Mediterranean. 



