8o Memoir Sears Foundation for Marine Research 



viously listed by Gray, 1851, as P/atyrAina sinensis); Schreiner and Ribeiro, Arch. Mus. nac. Rio de J., 



12, 1903: 80 (listed, Rio de Janeiro); Ribeiro, Pescas 'Annie,' 1904: 18 (nos., Ilha Rasa, Brazil); Arch. 



Mus. nac. Rio de J., 14, 1907: 175, 207 (diagn., refs., Rio de Janeiro and Bahia, Brazil); Fauna Brasil., 



Peixes, 2 (l) Fasc. i, 1923: 31, pis. 12, 13 (diagn., photos, male and female, Rio de Janeiro and Bahia, 



Brazil). 

 Syrrhina bnvirostris Garman, Bull. Mus. comp. Zool. Harv., ly, 1888: 89, pi. 25 (mucous canals); Mem. 



Harv. Mus. comp. Zool., j6, 1913: 285, pi. 65, fig. 3 (descr., ill. skel., Rio de Janeiro). 

 Zapteryx brevirostris Norman, Proc. zool. Soc. Lond., 1926: 943 (in Key), 980, fig. lE (ill. nostril, size, refs. 



Brazilian specimen in Brit. Mus.). 



Suborder TORPEDINOIDEA 

 Electric Rays, Torpedo Rays 



Characters. Trunk anterior to cloaca a depressed subcircular disc, fleshier toward 

 its margins and thicker there than in most other disc-shaped batoids, the body softer. 

 Tail rather sharply marked off from body sector, with or without lateral folds; broader 

 basally than in any other batoids except the Sawfishes (Pristoidea) and Guitarfishes 

 (Rhinobatoidea) ; as long as body in some, but shorter than body in most, and reduced 

 in some to a mere rudiment bearing the fins.^ Attachment of anterior parts of pectorals 

 to sides of head extending forward to or beyond level of eyes. One or two well developed 

 dorsal fins, or none; the first (if there are two) partly over or close behind bases of 

 pelvics. Caudal fin well developed, its axis raised but slightly if at all. Pelvics with 

 outer margins continuously convex in most cases but somewhat emarginate in some, 

 so deeply so in one genus that the anterior subdivision forms a separate limb-like 

 structure arising from the lower surface of the disc some distance inward from the 

 margin^ (as in some genera of Rajoidea also, pp. 314, 327). Inner posterior margins of 

 pelvics free from sides of tail in some species but united with it in others. 



Eyes small, functional in most species, but rudimentary or even entirely obsolete 

 in a few deep-water forms. Spiracles either close to eyes or separated from the latter 

 by a narrow interspace, their margins either smooth or with larger or smaller knobs 

 or papillae. Nostrils close to mouth but entirely separate from it, their anterior margins 

 expanded and joined together as a single curtain-like flap with median attachment 

 roofing over inner parts of nasal openings and extending rearward nearly or quite to 

 the mouth. Mouth small to moderate in size; widely distensible in some genera, with 

 the upper and lower jaw cartilages but loosely articulated together; more or less 

 protractile in others, with the jaws not only firmly articulated but also bound together 

 on either side by a labial cartilage of two elements with special muscles, thus limiting 

 the gape (see also p. 108). Gill openings small. Teeth small, rounded, or with one to 

 three more or less prominent cusps; in 12 to about 64 series in different species, 

 arranged in bands that terminate some little distance short of either corner of mouth; 



1. Genus Hypnos, p. 87. 



2. This is the case in Typhlonarke, a genus of Narkidae (i. e., with one dorsal fin), founded by Waite (Rec. Canter- 

 bury [N. Z.] Mus., I [2], 1909: 146) for an Electric Ray first described as Astrape aysoni Hamilton (Trans. N. Z. 

 Inst., J4, 1902: 25, pis. 10-12). 



