276 



BULLETIN OF THE BUREAU OF FISHERIES. 

 Genus UROBATIS Garman. 



30. Urobatis sloani (Blainville). 



Urolophus jamaicensis, Gudger, 1913a. p. 4; Coles. 1914, p. 93. 



23 



Teeth. — "Teeth broader than long, lozenge-shaped on the crown, sharp in males, in — rows in 



27 , 

 eight-inch specimen, -~ in fourteen-inch." " 



Armature of skin. — " Skin rough with small spines on head, dorsum and top of tail to upper edge of 

 caudal; outer portions of disk, on pectorals and ventrals, and lower surfaces are smooth." " 

 There is a stout spine inserted at about the middle of the tail. 

 Coles capttu"ed a small example at Cape Lookout in June, 191 1. 



Genus PTEROPLATEA MUUer and Henle. 



KEY TO THE SPECIES. 



a. Caudal spine normally absent (reported to be present in very large examples); tail about one-fourth 



length of body ; no tentacle behind spiracle micrura. 



aa. Caudal spine present at all ages; tail larger, nearly half length of body; a tentacle behind 

 spiracle altavela. 



31. Pteroplatea micrura (Schneider). 



Pteroplaiea tnadura. Yarrow, 1S77, p. 216; Jordan and Gilbert. 1879, p. 386; Jordan. 1886. p. 26; Jenkins, 1887. p. 84; Wilson, 

 1900. p. 3S5'. Linton. 1905. p. 348; Smith. 1907. p. 45; Gudger. 1912. p. 14.'^: Coles. 1914. p. 93. 



77 • ... 



Teeth. — In a male about 30 cm. long, the teeth are in ii rows, minute, arranged in quincunx, similar in 



form in both jaws; outline of teeth spear-shaped, cusps narrow, elongate, sharp-pointed . curv'ed outward 

 and backward; broad basal portion channeled, edges curved outward, so tliat the anterior margin of the 



A B 



Fig. 26.^A, Teeth, upper and lower jaws.cf a female, Pteroplatea micrura, 37 cm. long. from Beaufort, N.C.; B, 

 teeth, upper and lower jaws, of a male, Pteroplatea micrura, about 30 cm. long, from Beaufort. N. C. 



tooth before mucous is cleaned away appears as a concave edge with pointed outer angles, the basal 

 portion being entirely concealed. 



In a female 37 cm. long the teeth are in about rrrows, in one 50.4 cm. long in about g^''°^^^- These 

 resemble the teeth of the male except that the pointed cusp is shorter, not markedly longer than basal 

 wings. 



Skin smooth; very large examples are reported to have a caudal spine. 



a Garman. The Flagiostomia, p. 402. 



