330 BULLETIN 10 0, UNITED STATES NATIONAL MUSEUM 



Skin largely smooth. Dermal fold along each side of tail. Above 

 eye 4 or 5 tubercles, 2 or 3 in median row at front of back and median 

 vertebral series on tail 12 to 23 to first dorsal. 



First dorsal length 314 to 314 in head; second dorsal length 2 to 

 31^ ; caudal small, shorter than either dorsal, longer with age ; pec- 

 toral broad, forms subcircular disk, outer edges widely convex; 

 ventrals broad, hind edges deeply notched; claspers broad, end in 

 obtuse points, length % hind ventral edges. 



Brown above, with pale translucent space each side of and between 

 rostral cartilages. Often disk darker medially and sometimes dark 

 blotch on pectorals basally and posteriorly. Under surfaces whitish, 

 with outer margins of pectorals and ventrals broadly brownish. 



China, Japan. My young examples do not show the "scattered 

 enlarged granules above the body cavity, around each of the twenty 

 or more small tubercles in the vertebral series, around each of those 

 in the two pairs on each shoulder, in the pair above each spiracle 

 and around each of the single ones at the front of the orbit. Small 

 tubercles in four or five series, the larger sharper granules appear 

 along the outer edges of the anterior half of the pectorals," as de- 

 scribed by Garman. These are all features with age. 



U.S.N.M. No. 51295. Tokyo. Jordan and Snyder. Length, 680 mm. 

 U.S.N.M. No. 71736. Tokyo market. Alhatross collection. Length, 220 to 230 

 mm. 2 examples. 



PLATYRHINA LIMBOONKENGI Tang 



Platyrhina limioonkengi Tang, Lingnau Sci. Journ., vol. 12, No. 4, p. 561, pi. 42, 

 figs. 1-2, 1933 (type locality: Amoy, China). 



Disk subcircular, broader than long. Snout obtuse, preorbital 

 length 2 or more times space between spiracles; preoral length 2y^ 

 times mouth width. Rostral cartilage reduced, not reaching end of 

 snout. Eye 8 to 9 in preorbital length of snout; eye and spiracle 2 

 in space between spiracles. Nostril connected with mouth by groove, 

 length equals or slightly longer than internarial width; front nasal 

 valves expanded, partly covering inner part of nostrils and not 

 joined across internarial space. Mouth slightly arched, no elevations 

 or depressions on jaws. Teeth small, in pavement, 82 to 88 rows 

 in lower jaw, each with short median keel. 



Most of disk densely covered with prickles, especially on snout, its 

 anterior margins and center of back and tail surrounding spines. 

 Each supraorbital ridge with 3 or more spines ; 2 pairs on shoulder 

 and 3 smaller on lateral border; row on median line of back to 

 ventral bases, sometimes down to tail; 2 rows on tail and 2 pairs 

 between dorsals. 



First dorsal twice high as long, origin nearer caudal than ventral 

 origin, reaching or almost reaching second dorsal origin. Inter- 



