DR. GUNTHER ON THE FISHES OF CENTRAL AMERICA, 491 
finely granular; a series of very 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 pre- 
ocular part of the snout yellowish white. 
One male, 21 inches long, was obtained by Capt. Dow on the Pacific coast of Panama. 
299. UROLOPHUS 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. AroBaTIs LaTIROSTRIS (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 remark 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. Duméril. 
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