68 CONTRIBUTIONS TO NORTH AMERICAN ICnTUYOLOGY IV. 



the outer extremities ; posterior convex ; inner straight a portion of .their 

 length. Ventrals truncate, rounded. Snout produced, forming a 

 rounded prominence in front of the margins of the disk. Lenglli from 

 the forehead less than the width of the head. A line joining the wider 

 portions of the disk passes nearer to the head than to the shoulders. 

 Tail more than twice as long as the body, without a trace of keel above ; 

 a long narrow expansion below has its origin opposite that of the spine, 

 and terminates in a keel which continues to the extremity, roughened 

 Avith small tubercles, with an irregular series of broad-based conical 

 tubercles on each side. A pair of large, compressed, erect tubercles 

 stands immediately in front of the caudal spine, and a similar oue is 

 placed over the middle of the pelvic arch. These suggest a continuous 

 series in larger specimens. Three larger elongated tubercles, with 

 points directed backward, similar to those of Z). /wisto/rr, occupy the mid- 

 dle of the shoulder girdle. Mouth curved, six (5-6 ?) papillre at the bot- 

 tom behind the teeth ; two of these are in the middle in front, where 

 usually tliere is but one. Color light olive, probably greenish in life, 

 white below. Distinguished from I), centrura by the prominent snout, 

 the shape of the tubercles in the middle of the back, and the narrowness 

 of the posterior portion of the disk. Length , of body 10, tail 35.3, and 

 width of pectorals 20.5 inches. Sent from the Sandwich Islands by 

 Andrew Garrett. 



Dasibatis sabina. 



Tnjijon aahina Lesueni', J.nur. Acad. Nat. Sci. Phil, iv, p. 109. 

 Trjigoii mlnnu Miiil. et Heiile, Plagiostomen, p. 1G3. 

 Tri/gon sabina Dumejil, Elasmobrauch. p. 607. 



Disk subcircular. Snout produced, blunt. Anterior margins of the 

 pectorals concave near the snout, becoming convex toward the broadly 

 rounded outer extremities ; hinder and inner margins convex. Upper 

 jaw with a deep indentation, receiving a corresponding prominence on 

 the lower. Teeth at the sides of this indentation much larger, resem- 

 bling the molars of JIeferodo7if us. Mouth with five papilloe. Tail less 

 than twice as long as the disk, tapering to a fine point, rough with small 

 l)rickles similar to those scattered over the head and back, a cutaneous 

 expansion above, and a broader, longer oue below. These end nearly 

 opposite each other, the lower extends forward under the spine. "With 

 a median row of tubercles on the dorsum and one or a i^air on each 

 shoulder. Distinguished from Utherculata by the shape of the snout, the 

 rounded pectorals, the shorter tail, the larger teeth, the greater cnrva- 



