EIXED-GILLED CHONDROPTEHYGIANS. 249 



the opposite one. The dorsal fins are almost always on the tail. The 

 ova are brown, coriaceous, and square, the angles extended into 

 points. We subdivide the genus as follows : 



Rhinobatus*, Sch?/, 



The Rhinobati connect the Rays with the Squali by their thick 

 fleshy tail, furnished with two very distinct dorsals and a caudal ; 

 the romboid formed by their snout and their pectorals is acute in front 

 and narrower in proportion than in ordinary Rays. Independently 

 of this they have all the characters of the latter genus ; their teeth 

 are crowded and planted in a quincunx order like small flat paving- 

 stones. 



Some of them still have the first dorsal on the ventrals f . 

 In others it is much further back. 



Such are the Mediterranean species, R. rhinobatus, L. ; 

 Will., D, 5, f. 1 ; and that of Brazil, R. ehctricus, Schn., Marcgr. 

 152, which has been said to participate in the properties of the 

 Torpedo; this, however, has not been proved. 



There is another species, Rh. granidatus, the skin of which is 

 granulated \. The 



Rhina, Schn. 



Only differ from the Rhinobat in a short, broad, and rounded 

 snout §. 



Torpedo ||, Dum. 



The Torpedos have the tail short, but still tolerably fleshy ; disk of 

 the body nearly circular, .the anterior border being formed by two 

 productions of the snout which incline side-wise in order to reach the 

 pectorals ; the space between these pectorals, head and branchiae is 

 filled on each side with a singular apparatus formed of little mem- 

 branous tubes placed close together like a honeycomb, subdivided by 

 horizontal diaphragms into small cells filled with a sort of mucus, and 

 traversed by numerous nerves proceeding from the eighth pair. It 

 is in this apparatus that resides the electric or galvanic power which 

 has rendered the Torpedo so celebrated; violent shocks are expe- 

 rienced by touching it, and it is most probable that the same power is 



* Rinobatos, which Gaza translates by Squatino-raia, is the Greek name of these 

 fishes, which were considered by the ancients as produced from the union of the Ray 

 with the Squatina. 



f Rhin. lavis, Schn. 77, Russel, 10, and Rh. Djiihleyisis, Forsk., IS, which probably 

 form but one species. It is to it must be referred the fig. of the Rhinobate, Lacep., 

 V, vi, 3, and that of Duhamel, part II, Sect. IX, pi. xv. 



X N.B. The 7?. thouin, Lacep., 1, 1, 3, is a variety of the common Rhinobatus. 

 The Rata halavi, Forsk., also appears to be the same. Add the Suttirara, Russ., XI. 



§ Rhina anrylostomus, Bl., Schn., 72, to which the editor improperly adds the 

 Raie chinoise, Lacep., I, ii, 2, which, as well as can be determined from a Chinese 

 figure, rather approaches the Torpedo. 



|| Torpedo, narke, ancient names of these fishes, derived from their benumbing 

 faculty. 



