254 bulletin: museum of compakative zoology. 



bases, beyond which point to the extremity the ridges are hardly distinguishable. 

 In either a transverse or a longitudinal section between the eyes the crown is 

 convex. Spiracle as large as the eye, with two rudimentary folds on the hind 

 margin of equal size and remote from one another. Nostrils comparatively small, 

 in width about two-thirds of the internarial space and elliptical in shape, rather 

 than short and broad and larger at one end than at the other, as is the case with 

 R. rhinobatos, R. thouini, and allies ; distance of the outer angle of one from that 

 of the other less than half the length of the snout. Anterior nasal valve small, 

 lateral extension from the free portion less than the length of the latter, not ex- 

 tended from the margin of the nostril. The anterior nasal valve is not continued 

 to the inner angle of the nostril ; it is not extended upon the internarial space ; in 

 fact it is carried very little of the distance from the free flap, or cirrus, toward the 

 angle. Scales very small, keeled or sharp-pointed on the upper surfaces, those 

 on the under surfaces more flattened. Compressed sharp tubercles appear in a 

 row on each rostral ridge, increasing in size backward ; three tubercles in front of 

 each orbit, and a couple at the inner edge of each spiracle. About twenty larger 

 tubercles occur between the back of the head and the first dorsal fin in a verte- 

 bral row ; there is a pair of tubercles at each side of this row on the shoulder 

 girdle, the inner one of each pair being the larger. A single tubercle stands at 

 the origin of the second dorsal fin. Of the dorsal fins the second is somewhat 

 larger than the first ; both are convex on the front margin and concave on the 

 hinder. The fin area of the caudal fin is small. 



Color an olivaceous-brown or brownish olive on the back, darker toward the 

 spinal column, dingy white at each side of the rostral cartilage and between the 

 ridges at its base, whitish on the lower surfaces. 



Type Cat. 807 M. 0. Z., from Ceylon. 



Raia kincaidii, sp. nov. 



On the fins of Raia kincaidii the angles are so broadly rounded that the disk is 

 best described as subround. The snout is of medium length ; it is outlined in 

 broad curves, and the tip has the appearance of an oblong or quadrangular slightly 

 produced inset ; the rostral cartilage is broad at the skull and tapers rapidly about 

 half the way to the tip, where it ends in a sharp point. The eyes are of medium 

 size ; they are prominent, and the interorbital space is slightly convex. Mouth 

 moderate, curved forward in the middle, as wide as the distance between the 

 shoulder spines, which is a little less than half that of the mouth cleft from the 

 tip of the snout. Teeth rather large, in thirty -three rows on the upper jaw and 

 thirty-one on the lower, with flattened crowns from which there is a raised sharp 

 cusp at the posterior margin. Gill clefts small, the greatest width not more than 

 half the length of the eye. Tail as long as the disk, depressed and strong 

 anteriorly, tapering gradually to slender, with a dermal fold on each side and 

 with a finlet behind the second dorsal. Dorsal fins equal, separated by a space 

 of the ocular width bearing one or more tubercles. Upper surface covered by 

 small, sharp, closely set hooked scales : a row of twenty-nine larger tubercles — 



