1909.] N. Annandale : Report on the Batoidei. 51 



A. Teeth in a single broad series . . . . . . Aëtobatis. 



B. Teeth in several series, of which the lateral ones are much 



narrower than the central one . . . . . . Myliobatis. 



Genus Myliobatis, Cuvier. 



This genus is sufficiently defined in the description of the family and the generic 

 key printed above. At least two species occur in Indian seas and have been taken 

 by the " Golden Crown," namely, M. nieuhofii and M. maculata. A new variety of 

 the former is described below. 



Myliobatis nieuhofii (Bloch and Schneider). 



Size moderately small (adults 42—64 cm. across the disk, young about 15 cm.). 



Disk considerably more than twice as long as the distance between the mouth and the 



vent to mouth 100 . „ i- t,.i j_ i- t,^i 



vent, the mdex .^rr — c a- -u varymg from slightly over 37 to slightly 



over 43, but usually being between 40 and 41. The pectoral fins acutely pointed, 

 their anterior margin nearly straight, their posterior margin broadly concave. 

 Snout (measured from anterior borders of skull) -^.^ to oV as long as the distance 

 between the mouth and vent and from I- to y as long as broad at the base, not 

 sharply pointed. 



Tail much longer than disk, without a serrated spine. The dorsal fin arises nearer 

 the base of the pelvic fins than their distal margin and does not reach, or barely 

 reaches, the level of that margin posteriorly. 



Colour. — The fresh fish has the dorsal surface of a bright greenish golden colour with 

 five broad cross-bars of a darker and more livid shade across the disk, and two 

 across the head. Not only do these markings disappear in spirit or even in ice, 

 but they are very superficial, and any rough handling causes the tissues which 

 contain them to be rubbed away. The ordinary spirit specimen of the adult 

 has the dorsal surface of a dark slate-grey. The cross-bars are more conspicuous 

 in the young and remain visible longer in spirit. The ventral surface is white. 



Sktn soft and at first sight naked. The back, however, is more or less completely 

 covered with minute, star-shaped denticles buried in the skin and sometimes ex- 

 tending on to the ventral surface. They can usually be felt by drawing the 

 tip of the finger across the back of the disk. 



Mouth nearly straight. The teeth truncate in front and not projecting from the jaw. 

 Their proportions are very variable and the number of series of smaller teeth at 

 the sides of the broad central one is not always the same on the two sides of one 

 jaw. The nasal flap is always straight. 

 As this is one of the most variable species with which I am acquainted, I have 



examined and measured a large number of specimens with the greatest care. The 



first result of this examination was to prove that two forms of the species existed side 



by side, one with the area immediately above the orbits smooth, the other with a 



