BULLETIN OF THE UNITED STATES FISH COMMISSION, 307 



1. Urolophus aspidurus, sp. nov. (29410, 29307, 29454.) 



Color i)laiu browu ; upper side of tail blackish ; under side of body 

 and tail white. 



Disk very slightly longer than broad, its length very little less than 

 length of tail ; anterior margins of disk nearly straight, the anterior tip 

 abruptly projecting as an exserted, narrow, triangular, promineuce 

 rounded at its end ; length of exserted part about as long as the width 

 of its base, and from half to two-thirds the interorbital width, it being 

 longer aud sharper in a male specimen, in which also the anterior mar- 

 gins of the disk form a less obtuse angle 5 distance from eye to tip of 

 snout about one-third length of the disk. Interorbital space broad, some- 

 what concave, 2J in distance to tip of snout. Eyes very small, nnich 

 smaller than the large spiracles, their diameter less than half interorbital 

 width. Width of mouth 2^ in its distance from the tip of the snout. 

 Nostrils directly in front of angles of mouth ; nasal folds forming a 

 broad continuous flap, the edges of which are slightly fringed. Ven- 

 trals projecting a little beyond outline of disk. Caudal spine very large, 

 its length a little more than twice interorbital width (in a large female 

 specimen duplicated, and as long as from eye to tip of snout), its inser- 

 tion well in front of middle of tail. Caudal fin long and low, the lower 

 portion longer, beginning nearly opposite tip of caudal spine. Depth 

 of tail with the caudal fin, about half interorbital width. 



Skin entirely smooth, with the exception of a series of strong broad- 

 rooted spines or bucklers on the upper part of the tail in front of caudal 

 spine, and sometimes a series of minute sand-like prickles on snout, and 

 on median line of body. These latter are present only in a large female 

 specimen, which also has 8 spines on the tail instead of 2 as in the 

 others. These spines are straight, sharp, directed backwards, their 

 height about equal to width of base, which is somewhat longer than 

 diameter of pupil. 



This species is not uncommon in the Bay of Panama, and is brought 

 into the market in company with Urolophus mnndus. Three specimens 

 were obtained, the largest about 18 inches in length. 



2. Tylosuriis scapularis, sp. nov. (29427,29435,29438.) 



Allied to Ti/losurus longirosiris (Mitch.), but the tail not depressed iiud without 

 cutaneous ridge. 



Body slender, net compressed, as broad as deep ; caudal peduncle 

 compressed, deeper than broad, without trace of cutaneons keel, the 

 lateral line not more conspicuous there than elsewhere, and not black. 



Head long, the jaws very long and slender, narrow throughout; length 

 of upper jaw from eye twice the length of the lest of the head. Diame- 

 ter of eye about equal to interorbital width, contained 8 to 9 times in 

 the length of the upper jaw, 3i times in the length of the rest of the 

 head. Teeth much as in T. hngirostris, the small teeth forming tlie ex- 

 ternal band, not very small ; the large teeth of the inner series slender 



