404 BULLETIN 10 0, UNITED STATES NATIONAL MUSEUM 



f. Tail IVs times disk length; oral papillae 9; bluish slate. 



agulhensia 

 f*. Tail once disk length. 



?-\ Oral papillae 5; 7 median spines on back; greenish-slate 



above schreineri 



i\ Oral papillae 3; spines stellate; slate gray, spotted with 



white brevicaudatus 



a*. Dasyatis. a cutaneous fold below tail, keel above ; disk broader than long ; 

 oral papillae 5; body smooth; tail IVj body lengths; brown, greenish to 



olive or grayish, with or without pale spots pastinacus 



a*. Amphotistius. A cutaneous fold below tail and another above ; disk broader 

 than long. 



;■'. No larger tubercles in vertebral row sinensis 



/". Tubercles in vertebral row narrow, depressed. 

 k\ Tail little over 2 disk lengths. 



l\ Back rough, with median row of tubercles ; oral papil- 

 lae 7; brown, olivaceous fluviorum 



f. Body smooth, only tail roughened terminally; oral 

 papillae 7; gray, with irregular blackish margins. 



ushiei 

 k\ Tail equals 2 disk lengths. 



m\ Oral papillae 3; median row of tubercles; above 



chocolate brown navarrae 



m-. Oral papillae 2; brown, with black-edged blue 



spots kuhlii 



k\ Tail less than 2 disk lengths. 



»\ Oral papillae 5 ; back smooth to rough, tubercles 

 broad based in vertebral and scapular rows ; 



brown olive to grayish brevis 



n^ Oral papillae 3 ; back roughened, tubercles ver- 

 tebral and humeral ; brown, uniform to clouded. 



akajei 

 w*. No oral papillae ; back smooth to rough, tubercles 

 in median row large ; brown, yellowish to red- 

 dish zugei 



k*. Tail once or more length of body. 



o\ Oral papillae 5 ; tubercles with stellate bases ; 



white, tail gray brown microps 



0". Oral papillae 4. 



p\ Olive, tail gray ; snout pointed ; tubercles 



rounded jenkinsii 



p^ Coloration uniform ponapensis 



o'. Oral papillae 3 uylenburg-i 



o^ Oral papillae 2. 



g\ Gray with blackish margins- marg'inatus 

 q-. Reddish brown, yellow spotted. 



imbricatus 



^. Brown, with 9 ill-defined, crescentic, 



brownish markings arched along middle 



of each pectoral granulatus 



