Fishes of the Western Nortli Atlantic 123 



1887, of Torpedo occidentalis was Narcinc brasiliensii; C. Lookout, N. Carolina); Coles, Copeia, 32, 

 1916: 46 (specific status). 



Probable Synonyms: 



tTorpedo occidentalis Jenkins, Johns Hopkins Univ. Stud. BioL, 4, 1887: 84 (listed, Beaufort, N. Carolina). 



Narcine entemedor ]orda.n and Starks, Proc. Calif Acad. Sci., (2) 5, 1895: 387 (descr., nos.. La Paz, Mazatlan, 

 Mexico); Gilbert and Starks, Mem. Calif Acad. Sci., 4, 1904: 15, 207 (descr., Panama Bay); Osburn 

 and Nichols, Bull. Amer. Mus. nat. Hist., J5, 1916; 144 (Pacif Coast, Mexico); Meek and Hildebrand, 

 Field Mus. Publ. ZooL, 75 (i), 1923: 74 (cf N. brasi/iensis); Breder, Bull. Bingham oceanogr. Coll., 

 2 (i), 1928: 5, fig. 2 (color, photos, Pacif Coast, Mexico); Beebe and Tee-Van, Zoologica N. Y., 28, 

 1941: 247 (color, ill.. Gulf of California). 



Tetronarce occidentalis Smith, N. C. geol. econ. Surv., 2, 1907: 43 (at least in part, C. Lookout, N. Carolina). 



Narcine brachypleura Ribeiro, Fauna brasil., Peixes, 2 (i) Fasc. i, 1923: 36, pis. 16, 17 (diagn., photos, adult 

 male, Brazil, supposed to differ from A'', brasiliensis in relatively narrower disc, but probably only an 

 extreme variant). 



Doubtful Synonyms: 



Narcine nigra Dumeril, Rev. Mag. Zool., (2) 4, 1852: 276 (cf N. brasiliensis, Brazil); Hist. Nat. Poiss., I, 

 1865: 515, pi. II, figs. 4, 4a (descr., color, ill. mouth, teeth, supposed to differ from N. brasiliensis in 

 shape of fins, rounded teeth and smaller eye; only one specimen seen); Bertin, Bull. Mus. Hist. nat. 

 Paris, (2) II, 1939: 82 (type specimen in Paris). 



Genus Diplobatis Bigelow and Schroeder 1948 



Diplobatis Bigelow and Schroeder, J. Mar. Res., 7 (3), 1948: 562; type species, Discopygc omrnata Jordan and 

 Gilbert 1890. Pacific Ocean, off coast of Columbia, 33 fathoms. 



Generic Characters. Nostril subdivided about midway of its length into two separate 

 apertures by a cross bridge of stiff tissue. Teeth entirely concealed within mouth 

 when latter is retracted and closed. ^^^ Median sector of each lip marked off at either 

 end by a deep transverse groove when the mouth is retracted. Characters otherwise 

 those of Narcine (p. 108). 



Size. The largest specimen reported was only 198 mm long. 



Range. Known only from the coast of British Guiana in the Atlantic and from the 

 Gulf of California to Panama in the Pacific. 



Species. Two species have been described, D. pictus from the Atlantic and Z). om- 

 rnata from the Pacific. D. pictus is distinguished from £). omrnata by angular pelvics 

 which are evenly rounded along their outer margins in the latter. Z). pictus has a disc 

 no wider than long and the tips of its dorsal and caudal fins are pointed, whereas in 

 D. ommata the disc is wider than long and the tips of the dorsal and caudal fins are 

 rounded. A conspicuous circular marking on the center of the disc, present on Z). om- 

 rnata^ is lacking on D. pictus. 



Key to Species 



I a. Disc scarcely as wide as long; tips of dorsals and caudal pointed; anterior margin 

 of pelvics not concealed by pectorals. pictus Palmer 1950, p. 124. 



166. In all other genera of the family in which the mouth is protractile [Narcine, Benthobatis, Discopyge, and probably 

 Heteronarce), the tooth bands extend so far forward that several of the anterior rows of teeth are fully exposed even 

 when the mouth is tightly closed. 



