UROBATIS. 401 



batus. Tail as long as the disk, with a low keel above near the end; subcaudal 

 fin as deep as the muscular portion, of equal depth to the end. 



Blackish brown above; below white with blackish edges on pectorals and 

 ventrals. 



Mauritius. 



Taeniura atra. 



Taeniura atra Macleay, 1883, Proc. Linn. soc. N. S. W., 7, p. 598. 

 Taeniura mortoni Macleay, 1884, Proc. Linn. soc. N. S. W., 8, p. 212. 



Disk broader than long, subround. Tail less than twice the length of the 

 disk, with a deep cutaneous fin under the terminal half. Skin rough with small 

 spines, depressed tubercles, three or four, in a vertebral series on the middle of 

 the disk, in the scapular region. 



Black, on the back of a sixteen inch specimen ; white below. 



New Guinea; Australia. 



Urobatis, gen. nov. 



Disk subcircular, angles and margins rounded, snout not produced. Teeth 

 small, numerous, tessellate, with acute cusps in the male. No median series of 

 tubercles. No dorsal fin. Ventrals short, moderately broad, subquadrangular, 

 directed backward. Tail about as long as the body, with a spine; caudals 

 rather deep, rounded. Embryo without an orbital process but with a long, 

 slender, pointed postspiracular process on the spiracular tegmen. 



Type U. sloani. 



Disk little longer than broad 

 tail about equal disk 



skin rough, no median tubercles 



brown, spotted with yellow . . . sloani (page 402) 

 brownish, vermiculate with yellow . vermiculatus (page 402) 

 Disk little broader than long 

 tail shorter than disk 



skin rough, no median tubercles 



brownish, clouded ..... nebulosus (page 403) 

 Disk subcircular 



tail shorter than disk 

 skin smooth 



brown, with yellow spots and vermiculations . halleri (page 403) 

 brownish gray, with spots of brown . maculatus (page 404) 



