46 Memoirs of the Indian Mitseum. [Vol.. II, 



(2) Large individuals of either sex measure about 22 cm. in length and 11 



cm. in breadth across the disk. 



(3) The posterior projection of the teeth is much shorter than the transverse 



diameter of the base, broader and blunter than is the case in AT', timlei. 



(4) The free edge of the nasal flap has a distinct projection in the middle line. 



(5) On the roof of the mouth, behind the teeth, a cutaneous ridge with 



irregular serrations occurs, while on the floor there is a similar ridge, 



with or without a notch in the middle line, but never divided into two 



distinct processes. 



The difference in colour between this species and A^. timlei is constant in fresh 



specimens, although naturally difficult to detect in faded ones. The difference in size 



exists as regards the smallest specimens I have seen. There are in the Indian Museum, 



from different localities, seven examples of A^. brunnea which measure between 55 mm. 



and 70 mm. in length, and between 30 mm. and 35 mm. across the disk. None of these 



specimens exhibits any trace of spots on the dorsal surface or retains any external 



rudiment of the yolk-sac. The smallest specimen of A^. timlei I have seen was taken by 



the ' ' Golden Crown ' ' at the mouth of the river Hughli in January, 1909. It measures 



80 mm. in length and 50 mm. across the disk and has numerous large ocelli on its 



dorsal surface. There is a yolk-sac 23 mm. long attached to the belly, and from the 



general appearance of the specimen I think that it was probably born prematurely. 



The structural differences between A^. brunnea and A^. timlei are of considerable 

 interest, but they can only be seen distinctly if the specimens examined are dissected. 



Genus BENTiiOBATis, Alcock. 



This genus, which is known from several specimens of a single bathybial species, 

 differs from Narcine mainly in the degeneracy of the eyes, a character of which no 

 trace can be detected in the only known deep-sea species {N . mollis) of the latter genus. 

 The teeth are not very different from those of some species of Narcine. 



Genus Astrape, Müller and Henle. 

 Tail with one dorsal fin. Eyes small but not markedly degenerate. Teeth nearly flat, 



with a broad, backwardly directed ridge, which is very bluntly pointed. Mouth 



protrusible but not tubular, the cleft nearty straight. Other characters as in 



Narcine. 



Only two species of this genus are recorded by Günther : Astrape capensis, from 

 the coast of S. Africa and Madagascar, with the tail distinctly shorter than the disk, 

 and A. dipterygia, from the seas of India, China and Japan, with the tail and disk of 

 about the same length. 



Astrape dipterygia (Bloch and Schneider). (PI. iiia, fig. 6.) 

 A. dipterygia. Day, Faun. Brit. Ind., Fishes, p. 46, fig. 19. 

 Disk longer than broad, of approximately the same length as the tau, somewhat 

 truncate in front. The pectoral fins well developed, especially posteriorly, thin 



