48 



Records of the Indian Museum. 



[Vol. XIII, 



Except for the fact that fig. 9 of his ilhistrations shows a tooth 

 on the outer margin of the external uropod — a cliaracter which 

 indicates that the species is not the same as Kishinouye's A. japoni- 

 ciis — there is nothing in Milne-Edwards' description to indicate 

 the precise identity of the form he examined. His material was, 

 however, obtained from the mouth of the Ganges, in which, so far 

 as I am aware, only one species exists, though three occur in the 

 Bay of Bengal. The principal specific characters are as follows :~ 



The eye is longer than in the other species and is a little 

 more than one-third the length of the carapace. The stalk is 

 rather more slender than usual and its length, in proportion to 

 that of the cornea, is greater. 



Fig. I. — Right .intennular peduncle in dorsal view. 



a. Acetes indicus, o". /. Acetes insularis, (f . 



b. „ „ ?. g. „ „ ?. 



c. Acetes erythraeus, ''low'" d" . h. Acetes japonicus, <f. 



d. „ „ g i. „ „ ?. 



e. , , , , " high " cf. 



The basal segment of the antennular peduncle in the female is 

 about the same length as that of the two distal segments com- 

 bined; the second segment is from 3 to 3^^ times, and the third 

 segment from 6 to 6J times as long as broad (text-fig. ib). In the 

 male the second segment is sometimes more slender than in females, 

 but the ultimate segment is always greatly elongated, much longer 

 than the first, and from 10 to 14 times as long as broad (text-fig. 

 la). 



The outer antennular flagellum of the male bears a single 

 large clasping spine, with finely serrate inner margin ; on the 

 segment opposite the tip of this spine there is a group of 5 to 7 

 close-set spinules. The two basal segments of the flagellum are 

 unusually long (text-fig. 2a). 



