32 PROCEEDINGS OF THE NATIONAL MUSEUM vol. m 



RHINOPTERA LALANDII Mttller and Henle 



Cow-nosed Rat 



Rhinoptera lalandii Muller and Henle, Systematische BeschreibungderPlagiosto- 

 men, p. 182, 1841 (Brazil). 



U.S.N. M. No. 123216, 1 specimen, 1,030 mm. in total length with length of 

 disks 360 mm., Piedras Bay, U. S. S. Niagara, March 14, 1925. 



U.S.N. M. No. 123219, head only, Amuay Bay, U. S. S. Niagara, May 15, 1925. 



Genus AETOBATUS Blainville 



Aetohatus Blainville, Bull. Soc. Philom. Paris, vol. 8, p. 120, 1816. (Genotype, 

 Raja narinari Euphrasen, designated by GiU.) (Ref. copied.) 



AETOBATUS NARINARI (Euphrasen) 



Eagle Ray; Chxjcho 



Rata narinari Euphrasen, Handl. Vet.-Akad. Stockholm, vol. 11, p. 217, pi. 10, 



1790 (St. Bartholomieu, West Indies.) (Ref. copied.) 

 Aetohatus narinari Rohl, Fauna descriptiva de Venezuela, p. 369, fig. 182, 1942 



(coast of Venezuela), 



U.S.N.M. No. 123218, smaU head, Amuay Bay, U. S. S. Niagara, May 15, 1925. 



Family MOBULIDAE 



Genus MANTA Bancroft 



Mania Bancroft, Zool. Journ., vol. 4, p. 144, 1828-29. (Genotype, Cephalop- 

 ierus manta Bancroft.) 



MANTA BIROSTRIS (Walbaum) 



Devilrat; Manta 



Raja hirostris Walbaum, Artedi's Bibliotheca ichthylogica, vol. 3, p. 535, 1792 



(on Diabolus marinus Willughby). 

 Manta birostris Rohl, Fauna descriptiva de Veneuzela, p. 370, 1942 (coast of 



Venezuela) . 



This giant ray may be recognized by the presence of a pair of fleshy 

 hornlike projections from the front of the snout that turn inward. 

 The eyes occur laterally near the outer base of each of the two fleshy 

 cephalic projections. 



Suborder Narcobatoidea 



Family TORPEDINIDAE: Electric Rays; Tembladores 



This family of rays has a disk-shaped body that tapers posteriorly 

 to a blunt thickish caudal fin; there are two small dorsal fins but no 

 "sting" or spine on the tail. The disk-shaped part of the body lateral 

 to and behind the eye is supphed with an electric gland capable of 

 giving a powerful electric shock when it is touched. 



