432 BULLETIN 10 0, UNITED STATES NATIONAL MUSEUM 



DASYATIS JENKINSII (Annandale) 



Trygon jenkinsii Annandale, Mem. In«lian Miis., vol. 2, p. 28, text fig. 4-a, 1909 

 (type locality: off Ganjam coast, India, 2.'i-27 fathoms). 



Dasybatus jenkinsii Garman, Mem. Mus. C'omp. Zool., vol. 36, p. 378, 1913 

 (copied). 



Head to hind spiracle ed<^e 3% in disk leno^h. Snout 1% in head 

 to hind spiracle edge, as seen above snout sharply pointed in broad 

 obtuse angle, not much produced; orbit 4^8, 2% in snout, 2"% in 

 interorbital ; month jaws feebly undulated; teeth white, practically 

 uniform in size, each with low transverse ridge situated near hind 

 edge and with distinct transverse depression in front; papillae on 

 mouth floor 4, 2 median rather well separated; interorbital 11/2 in 

 head to hind spiracle edge. Spiracles close behind eye, subequal 

 with orbit. 



Skin fairly tough. Few enlarged rounded denticles in scapular 

 region, followed posteriorly by single row of stout, short, retroverted 

 spines with flat bases, row extending on tail to base of anterior spine ; 

 middle of back occupied by pavement of small, flat, round scales, 

 gradually smaller toAvards periphery. Tail covered by small blunt- 

 ly spinous tubercles. Pectorals and ventrals naked. 



Tail cylindrical, without folds, not much longer than disk width, 

 sometimes with 2 long, slender spines; pectorals form broad sub- 

 quadrangular disk, length I1/5 in its width which greatest just behind 

 spiracles, outer angles rounded, front edges linear, hind edges con- 

 vex. 



Dorsal surface reddish olive, paler at edges of fins, wnthout def- 

 inite markings. Tail dark gray, mottled on ventral surface with 

 brown and white at base. Ventral surface of disk dead creamy 

 white. Length, 192 mm. (Annandale.) 



India. According to Garman possibly a variety of Dasyafis 

 uarnak. 



DASYATIS PONAPENSIS (Giinther) 



Trypan potiapciisi.s GiJNTHKR, Joiirn. Mus. Godcffroy, pt. 17, p. 493, 1910 (type 



locality: Kubary, Tonape, Carolines). 

 Dasybatus ponapensis Gabman, Mem. Mus. Comp. Zool., vol. 36, p. 380, 1913 



(copied). 

 Dasyatis ponapensis Fowlkk, Mem. Bishop Mus., vol. 10, p. 24, 1928 (compiled) ; 



Proc. 4th (1929) Pacific Sci. ('ongr., .Java, p. 50, 1930 (reference). 



Head to hind edge of spiracle 8% in total length. Snout 1% in 

 head to hind spiracle edge, as seen above broadly rounded with very 

 slight prominence; eye 4, 2% in snout, wide as orbital protrusion, V^ 

 in firm interorbital, 3% across entire interorbital width; dental 

 plates undulated; 4 papillae on mouth floor, as pair medially be- 

 hind lower dental plate and 1 each side near mouth angle; inter- 

 narial 21/10 in preoral length, flap with entire edge; interorbital V/g 



