390 CALIFORNIA ACADEMY OF SCIENCES. 18 
from Acapulco and from’ Panama, and by Evermann & 
Jenkins from Guaymas. 
18. Pteroplatea crebripunctata Peters. MANTARAIA. 
Very common on sandy shores everywhere about Ma- 
zatlan, from which locality it was originally described; 
also taken by Dr. Gilbert. 
Width of disk twice length to posterior end of anal shit; 
snout forming a regular curve from a little in front of 
middle of pectorals, a very small blunt projection at tip; 
anterior margin of disk convex near snout and lateral 
angles, pectorals concave medially ; posterior margin 
weakly convex; posterior angle broadly rounded; lateral 
angle sharply rounded; distance from snout to a line drawn 
through lateral angles, 2% times in distance to tip of tail. 
Interorbital a little wider than its distance to tip of snout; 
eyes twice spiracles; mouth equals snout, 6% in disk. 
Tail rat-like, with a scarcely perceptible fold of skin on 
its dorsal side. 
Ground color olive brown, everywhere with small dark 
points, not so close set as in Pteroplatea rava, indis- 
tinct greyish spots, half as large as iris, scattered over 
the body among the dark points, these spots are more dis- 
tinct on anterior edge of disk; tail mottled with darker; 
lower parts light. Markings nowhere so distinct as in 
the next species. 
Several specimens, the largest 15 inches long. 
19. Pteroplatea rava Jordan & Starks, n. sp. MAn- 
TARAIA COLORADA. 
One specimen taken in the Astillero at, Mazatlan. 
Length of disk 134 width; snout forming an angle 
which is almost a right angle: pectorals slightly concave 
medially; posterior margin of disk weakly convex; pos- 
terior angle not broadly rounded, but curved in some- 
what suddenly; lateral angles acute. 
