DE. GtJNTHEE ON THE FISHES OE CENTRAL AMEEICA. 491 



finely granular; a series of veiy small, distant, smooth, oblong tubercles along the 

 median line of the back. Nostrils longer than the space between their posterior 

 extremities, but shorter than the mouth. Upper parts uniform ashy brown, the prae- 

 ocular part of the snout yellowish white. 



One male, 21 inches long, was obtained by Capt. Dow on the Pacific coast of Panama. 



299. Ukolophus mundus. 

 Urotrygon mundus, Gill, Proc. Ac. Nat. Sc. Philad. 1863, p. 173. 



Mr. Gill proposes the generic name of Urotrygon for U. torpedinus and the present 

 species, the new genus being distinguished by the rounded and not angular outline, the 

 longer tail and posterior insertion of the spine, and especially the acute teeth. The 

 new species is thus characterized: — 



The disk is orbicular, with a slight linguiform projection in front, and with the 

 pectoral fins behind broadly rounded. The distance of the snout from the hinder 

 margin of the pectorals equals the width of the disk. The tail (behind the anus) is 

 rather longer than the body (in front). The spine is inserted behind the middle of the 

 tail, and is about as long as the distance between the snout and the nostrils. The 

 ventral fins extend outwards, the rectilinear anterior margin tending little backwards; 

 and the external margins are on a line with and complete the outline of the disk. The 

 posterior margin in the male is nearly rectilinear, while in the female it is slightly 

 convex, especially towards the inner angles. The upper velum is very sinuous and 

 fimbriated. The teeth are pointed and pyramidal. The spiracles are oval, interrupted 

 at the intero-anterior angle by the eyes ; and the margins are entire and well defined. 

 The skin is beset with numerous small stelliform tubercles, larger on the dorsal region. 

 The colour is a uniform dark brown above. 



Two small specimens, male and female, were collected by Capt.- Dow on the Pacific 

 coast of Central America. 



300. Aetobatis latieostris (A. Dum.). 



This species was known from one very young example only, from the west coast of 

 Africa; Messrs. Dow and Salvin have rediscovered it in the Bay of Panama. The 

 specimen, which to the root of the tail is 12 inches long, and has a tail of 44 inches, 

 does not differ in anything from the Atlantic example. I may reniai-k here that the 

 soft rostral appendage is naturally bent upwards, like the nose-leaf of certain Chiroptera, 

 and is not horizontally stretched forward as represented by M. A. Dumeril. 



3x2 



