RHAMPHOBATIS ANCYLOSTOMUS. 267 



rostrum short, trough-shaped; snout blunt 

 pectorals in part entering the snout 



nasal valves not forming an upper lip . Syrrhina (page 284) 

 pectorals not entering the snout 



nasal valves forming an upper lip Trigonorrhina (page 287) 



Rhamphobatis. 



Rhamphobatis Gill, 1861, Ann. N. Y. Lye, 7, 408 (name only). 



Head, body, and tail depressed; snout broad, blunt, rounded. Pectorals 

 not extending beyond the jaws, united with body and head in a subtriangular 

 disk forming ^bout one third of the total length. Tail nearly half of the total, 

 slender, continuous with the body to the pectorals; caudal axis raised in the 

 fins, subcaudal lobed. Ventrals remote from the pectorals. First dorsal above 

 the ventrals. Nostrils nearly transverse. Mouth arched forward, undulated; 

 teeth larger on the prominences. Spiracles large, without folds. Scales small; 

 tubercles large, compressed. 



Rhamphobatis ancylostomus. 



Rhina ancylosto7nus Scunewer, 1801, Bloch Ichth., p. 352; Cuv., 1817. Reg. anim., 2, p. 133; Gray & 

 Hardwicke, 1834, 111. Ind. Zool., pi. 102, f. 2; Agass., 1835, Rech. poiss. foss., 3, p. 82, pi. H, 

 f. 3, 4; MtJLLER & Henle, 1841, Plagios., p. 110; Richardson, 1846, Rept. Brit, assoc. adv. 

 sci., for 1845, p. 195. 



Rhina anchylostomus Schneider, 1801, Bloch Ichth., pi. 72; Bleeker, 1852, Verh. Bat. gen., 24, 

 p. 51, 56. 



Rhina cyclostomus Swainson, 1839, Class., 2, p. 322. 



Rhamphobatis ancylostomus DvmeriIj, 1865, Elasm., p. 482; Annandale, 1909, Mem. Ind. mus., 2, p. 10, 

 pi. 5, f. 5. 



Rhynchobatus ancylostomus GtJNTH., 1870, Cat. fishes Br. mus., 8, p. 440; Day, 1878, Ind. fishes, p. 730, 

 pi. 193, f. 3. 



Disk nearly one third of the total length, broader than long; snout semi- 

 circular in front, short, broad, angle from opposite the nostrils about 75°; 

 rostral cartilage short, broad, ridges widely separated. Crown transversely con- 

 cave. Nostrils rather narrow, two thirds of interspace, nearly transverse ; valves 

 feeble, anterior lobe short. Mouth medium, wider than the internarial space, 

 slightly arched forward and undulated, teeth on the prominences larger. Spir- 

 acle as large as the eye, without folds. Pectorals small, outer angle produced. 

 Dorsals of moderate size, angles produced; origin of first dorsal opposite that of 

 the ventral, second dorsal smaller. Ventrals small, origins distant from the ends 

 of the bases of the pectorals more than a length of the base of the first dorsal, 

 outer angles sharp. Tail depressed, tapering regularly with the body from the 



