8 ON NEW GENERA AND SPECIES OF FISHES 
This species is distinguished from Dasyatis gymnura 
(Muller)* by the shape of the snout, which in that species 
is “produced and sharp-pointed’’; by the convexity of 
the posterior border of the disk ; by the much shorter tail, 
which in gymnura is thrice the length of the disk ; and by 
its genera] smoothness. In some respects it approaches 
Dasyatis sabina (Le Sueur), which is, like it, a strictly 
estuarine and fiuviatile species. 
EXOCTID. 
EXONAUTES FULVIPES sp. nov. 
D. 12; A. 12; Se. 52—7. Depth of body 6, length 
of head 4# in the length of the body. Head a little wider 
than deep, its width equaling its length in front of the hinder 
margin of the eye. Snout + of the diameter of the eye, 
which is 22 in the length of the head, $ of the postorbital 
region, and equal to the concave interorbital width. Gill- 
rakers 19 on the lower branch of the anterior arch, the 
last 3 tubercular, the longest 4 of the diameter of the eye. 
Second pair of upper pharyngeal bones separate, armed 
with slender, conical, setaceous teeth; third pair fused, 
forming together a half-moon-shaped bone, which is densely 
clothed mesially with coarse scalpriform teeth, laterally 
with much smaller tricuspid teeth; lower pharyngeals 
united to form a sagittate bone, armed with small tricuspid 
teeth and a few somewhat enlarged and scalpriform teeth 
posteriorly.— Dorsal fin moderately high, its second and 
highest ray 4, its basal length * of the length of the head : 
anal originating below the 2nd. ray of the dorsal, which 
also slightly overlaps it, its length 2 of the head: upper 
* Trygon gymnura Miller, in Ermann, Reise um die Erde, p. 25, 
pl. xiii, 1830, is identical with T. tuberculata (not Bonnaterre 1788) Shaw, 
Gen. Zool., v, p. #90, 1804 (after Lacépéde’s Raie tuberculée) and Giinther, 
Catal. Fish., viii, p. 480, 1870. The latter author records it from Sydney, 
confounding it with one of our eastern species, possibly my D. thetidis. 
(Mem. Austr. Mus., no. iv. pt. i, p. 46, 1899). 
+ There is abundant evidence to show that all the teeth were originally 
tricuspid, those which are now apparently chisel-shaped having had the 
cusps worn down by continuous trituration. 
