ELIPESURUS STIIOGYLOPTERUS. 425 



characterized. The short spiny tail, without a serrated caudal spine, and the 

 positions of eyes and spiracles, remove it sufficiently from either Potamotrygon 

 or Disceus. E. strongylopterus, in lacking the tubercles and possessing a serrated 

 caudal spine on the tail, differs from the type. It is included only as a doubtful 

 species, and it may not belong to the genus. 



Elipesurus spinicauda. 



Elipesurus spinicauda Schomburgk, 1843, Fishes Guiana, 2, p. 184, pi. 23; Dum^iril, 1865, Elasm., p. 

 582; GtJNTH., 1870, Cat. fishes Brit, mus., 8, p. 472; Eigenmann, 1892, Proc. U. S. nat. mus., 15, 

 p. 25 (name only); Ribeiro, 1907, Arch. Mus. nac, 14, p. 184. 



Disk oval, about 18 inches in length by 14i or 15 in width. Eyes large, 

 prominent, hds with a process behind the orbit. Nostrils very large. Spiracles 

 large, without a process on the outer margin. Tail short, without a serrated 

 spine, but with strong spiny excrescences covering its base, the only organs of 

 defence with which the animal is furnished. Schomburgk's figure shows the tail 

 tapering to a point, as if complete, and to be about one third of the length of the 

 disk. The eyes are in the anterior fifth of the disk. 



Bright ochreous yellow, covered with a series of dark reticulated markings 

 the meshes of which are about the size of the eye. Our only information con- 

 cerning this animal is contained in the description and figure published by 

 Schomburgk. The form differs from the species of Disceus in the anterior posi- 

 tion and large size of eyes and spiracles, and in lacking the spiracular process 

 and serrated caudal spine. Though it is a doubtful species, it is one that, like 

 Elipesurus strogylopterus, collectors may yet hope to secure. 



? Elipesurus strogylopterus. 



Trijgon strogylopterus Schomburgk, 1843, Fishes Guiana, 2, p. 183, pi. 22; Muller & Troschel, 1848, 



Schomburgk's reisen, 3, p. 642. 

 Trygon (Himantura) strogylopterus Dumeril, 1865, Elasm., p. 592. 

 Trygon strongyloptera Gunth., 1870, Cat. fishes Brit, mus., 8, p. 476. 

 Paratrygon strongylopterus Eigenmann, 1892, Proc. U. S. nat. Mus., 15, p. 24 (name only). 

 Ellipesurus strongylopterus Ribeiro, 1907, Arch. Mus. nac, 14, p. 184. 



Disk circular, about as long as wide. Tail about one third as long as the 

 disk, thick at its insertion, becoming suddenly attenuate and continuing slender 

 to the end, armed at a short distance from its extremity by a serrated spine. 



Yellowish umber-brown with a narrow border of dull reddish brown; the 

 whole surface covered over with irregular markings and freckles of dark umber- 

 brown. Not recognized since Schomburgk. Differs from Elipesurus spinicauda 



