510 PISCES (CARTILAG.) PLAGIOSTOMI. [RAIA. 



British species belongs to the Torpedo marmorata of Risso. According 

 to Blainville, who regards Risso's species as mere varieties, the T. Gal- 

 vani of that author is the one most commonly met with on the shores 

 of the Mediterranean. This fish, at least the British species, attains to 

 a large size : according to Pennant, it has heen known to weigh above 

 eighty pounds. The exact use of the electrical apparatus is not well 

 ascertained. It is generally supposed to serve as a means of defence, 

 or to assist the fish in securing its prey, which is said to consist of other 

 fish. Mr. Couch imagines that it is connected with the functions of 

 digestion *. 



(2. RAIA, Cuv.) 

 * Snout sharp ; more or less elongated. 



199. R. Batis, Linn. (Skate.) Snout sharp, conic, 

 the lateral margins not parallel : skin granulated above : 

 one or three rows of spines on the tail ; the points of the 

 lateral rows, when present, directed forwards : colour be- 

 neath gray, with black specks. 



R. Batis, Linn. Syst. Nat. torn. i. p. 395. Block, Ichth. pi. 79. 

 Turt. Brit. Faun. p. 110. Flem. Brit. An. p. 171. Blainv. Faun. 

 Franq. p. 13.? R. laevis undulata, seu cinerea, Will. Hist. Pise. 

 p. 69. tab. C. 5. Ray, Syn. Pise. p. 25. Skate, Penn. Brit. Zool. 

 vol. in. p. 82. pi. 9. Id. (Edit. 1812.) vol. in. p. Ill, and Sharp- 

 nosed Ray, pi. 11. La Raie blanche ou cendree, Cuv. Reg. An. 

 torn. n. p. 398. 



LENGTH. From two to four feet ; sometimes more. 



DESCRIPT. (Form.) Form rhomboidal ; the transverse diameter greater 

 by one-third than the length, this last being measured from the extremity 

 of the snout to the vent : body thin, in proportion to its bulk : snout con- 

 siderably elongated, sharp, conical, the lateral margins never becoming 

 parallel, but approaching gradually to form an acute angle : teeth nume- 

 rous, in several rows, rather closely compacted, oval and broad at the 

 base, each terminating above in a sharp conical point, hooked, the hooks 

 inclining backwards, and most developed in the inner rows, and on the 

 central teeth in those rows: nostrils in a line with the angles of the 

 mouth, with which they are connected by means of a prolonged channel, 

 and placed at less than one-third of the distance from the mouth to the 

 margin of the pectorals: eyes of moderate size: spiracles large: skin 

 finely granulated above, communicating a slight roughness to the touch ; 



(3.) T. marmorata, Hiss. torn. in. p. 143. pi. 4. f. 9. T. Corpore carneo, 

 maculis fuscis, fasciisque sinuosis, marmorato ; cauda crassa, summitate rotundata. 

 La Torpille marbr6e, Blainv. Faun. Frun$. pi. 9. 



Spiracles surrounded by seven tooth-like processes : branchial openings crescent- 

 shaped : electrical apparatus very distinct. 



(4.) T. Galvani, Riss. torn. in. p. 144. T. Corpore fulvo, immaculate, nigro- 

 marginato. 



La Torpille Galvanienne, Cuv. Reg. An. torn. ir. p. 397. 



Differs from the three preceding species in its much larger dimensions, and in 

 the upper part of the body being constantly of a uniform red colour, without any 

 spots or markings whatever. 



* See Linn. Trans, vol. xiv. pp. 89, 90. 



