290 THE PLAGIOSTOMIA. 



Dark olive-brown, each of the three small tubercles at each side of the 

 interorbital space, each of the three on the middle of the back and each of those 

 in the two pairs on each shoulder surrounded by whitish or light yellow. Lower 

 surfaces white, blotched, or clouded with olive beneath the hinder parts of the 

 pectorals, the ventrals and the tail. 



Specimen described from Japan. Alan Owston. 



Platyrhinoidis. 



Platyrhinoidis Garman, 1881, Proc. U. S. nat. mus., 3, p. 522. 



Disk wider than long, very broadly rounded in front and at the sides. 

 Snout short, not projecting; pectorals extending to the end, where they are 

 separated by a wide space at each side of the rostrum. Rostral cartilage short, 

 broad at the base, tapering to the end. Nostrils nearly transverse; anterior 

 valve slightly extended on the internarial space beyond the nostril. Mouth 

 bow-shaped with a shallow upper lip across the entire width. Eye small. Spir- 

 acles large, close to the eye, without folds. Dorsals small, far behind the ven- 

 trals, without a posterior angle. Tail slender, with wide dermal folds; caudals 

 elongate. 



Platyrhinoidis triseriata. 



Platyrhina triseriata Jordan & Gilbert, 1880, Proc. U. S. nat. mus., 3, p. 36. 



Platyrhinoidis triseriata Garman, 1881, Proc. U. S. nat. mus., 3, p. 522; Jord. & Everm., 1896, Bull. 47, 



U. S. nat. mus., p. 65. 

 Rhinobatus triseriatus Jordan & Gilbert, 1882, Bull. 16, U. S. nat. mus., p. 64. 



Disk subround, broader than long; body about three sevenths of the total 

 length. Pectorals very broad, wider in front of the shoulder girdle, reaching 

 the end of the snout. Snout short, broad, rounded; rostral cartilage strong, 

 broad at the base, tapering to a point; ridges distant from one another at the 

 fontanel, confluent at the ends. Nostrils nearly transverse, narrower than the 

 interspace; outer section of anterior valve rudimentary, inner continuous with 

 the lobe, slightly extended on the internarial space; posterior valve with outer 

 section little curved at end of nostril, inner section and lobe feeble. Mouth 

 bow-shaped, width more than two thirds of the length of the snout; teeth small, 

 in 82 rows on the upper jaw of a twenty- two inch specimen. Crown broad, 

 concave transversely. Eye small. Spiracles larger, close to the eye. Pectorals 

 converging little at the sides of the rostrum. Ventrals close to the pectorals, 

 without notches. Dorsals small, equal, shaped like those of Raia, narrow with 

 hinder and lower margins a continuous curve; base of first dorsal, more than four 



