DASYBATUS SABINUS. 397 



without trace of angles. Mouth with five papillae, outer small; upper jaw in- 

 dented in the middle. Ventrals broad, truncate, angles rounded. Tail less than 

 one and one half times the length of the disk, with a short, elevated fold behind 

 the spine and a longer deeper one below. The folds widen backward and end 

 opposite one another. Disk naked in young. Adults have three rows of tu- 

 bercles on the back placed as those of D. hastatus. A large specimen from Payta, 

 has three broad-based tubercles in front of the caudal spine and the tail is rough- 

 ened with smaller ones. The short rows on the shoulders contain from one to 

 four tubercles each. 



This species differs from D. hastatus in the shorter tail, the rounder disk, 

 and in the shapes and sizes of the tubercles and the fin folds; it differs from D. 

 sayi in a greater development of fin folds and in their shapes and length. These 

 folds on D. hrevis are short and deep; they rise gradually and end abruptly. 



Olive or greyish brown, reddish near the edges; white below, with round 

 spots of brown under the base of the tail. 



Length of body 17, of tail 23, and width of disk 18 inches. 



In a young male the length of body is 8.1, of the tail 12, and the width of 

 the disk 9.2 inches. 



Taken at Payta, Peru, and San Diego, Cal., by the Hassler Expedition. 



DaSYBATUS SABINUS. 



Trygon sabina Lesuettr, 1824, Journ. Acad. nat. sci. Phil., 4, p. 10 extra, pi. 4, Raia sahina; Muller 



& Henle, 1841, Plagios., p. 103; Dumeril, 1865, Elasm., p. 607. 

 Trygon osteoslida Muller, 1835, Erman's reise, p. 25, pi. 14. 

 Trygon tuberculatus Dumeril, 1865, Elasm., p. 605; Gunth., 1870, Cat. fishes Brit, miis., 8, p. 480 



(part). 

 Dasyatis sabina Jordan & Gilbert, 1882, Bull. 16, U. S. nat. mus., p. 49; Jord. & Everm., 1896, Bull. 



47, U. S. nat. mus., p. 49. 

 Dasibatis sabina Garman, 1882, Bull. 16, U. S. nat. mus., p. 68. 



Disk subcircular, anterior margins waved, concave opposite the nostnls, 

 meeting in an angle that is little less than 90°, outer angles broadly rounded, 

 hinder and inner margins convex. Mouth moderate, with five papillae at the 

 bottom, with jaws abruptly bent forward in the middle of each side, and with 

 symphyseal angles rather broad, or truncate. Teeth small unequal, with sharp 

 cusps at the symphysis, on the males, in forty-eight rows on the upper jaws of 

 an adult of ten inches in width. Top of head and middle of back somewhat 

 roughened by small spines; a median row of sharp, elongate, compressed and 

 depressed tubercles on back and on base of tail, and one or two similar tubercles 

 at each side of it on the shoulder girdle. Tail less than twice the length of the 



