PSAMMOBATIS BREVICAUDATUS. 371 



Disk nearly round, anterior margins straighter, hinder margins and angles 

 rounded. Snout slightly prominent. Eyes rather small. Spiracles nearly as 

 large as the eyes. Mouth rather straight; teeth on the upper jaws in thirty-six 

 rows on a specimen of about seven inches in length. Nostril with two valves, 

 outer tubular. Vent near the middle of the total length. Ventrals rather large, 

 deeply notched, partly covered by the pectorals. Upper surfaces covered with 

 small sharp spines; larger tubercles in the median row and the lateral rows along 

 the middle of the tail and back. 



Brownish with a few spots of white and numerous small spots of brown, 

 larger toward the middle and above the abdomen, forming transverse bars on 

 the tail. 



Total length 7j, tail from vent 3§, and width of disk 5 inches. 



Sandy Point; Cape Virgins; Porto Bueno. 55 fathoms. 



PSAMMOBATIS BREVICAUDATUS. 



Psammobatis brevicaudatus Cope, 1877, Proc. Amer. philos. soc, 17, p. 32; Fowler, 1910, Proc. Acad. 

 nat. sri. Phil., 62, p. 471, fig. 2. 



Disk broader than long, anterior, outer and hinder margins and angles 

 broadly rounded; snout produced like a small papilla between the ends of the 

 pectorals. Ventrals not very deeply notched. Width between orbits greater 

 than length of orbit and spiracle. Top of head and a band along the anterior 

 part of the disk, above and below, rough with minute spines; disk elsewhere 

 smooth, excepting two spines in front of each orbit, a spine near the inner border 

 of each spiracle, a row of a few spines near the edge of the disk opposite the eyes, 

 a median row of six. or eight on the middle of the back, a double row parallel to 

 the edge of the pectoral and a median series on the tail. Tail much shorter 

 than the body, one fifth longer than the claspers, with broad lateral folds, two 

 dorsals, and a rudimentary caudal. Back plumbeous with darker shades; mid- 

 dle of anterior part of muzzle pale with a dark spot behind it. The measurements 

 accompanying the description are probably incorrect. The total length is given 

 as a little more than 12 inches (m. 0.307), the width nearly 10.6 (m. 0.270), 

 and the length of the body to the vent about 7.48 (m. 0.190). The parallel rows 

 of spines on the pectorals are the tenacula of the male. 



Bay of Pacasmayo, Peru. 



