1922.] W. M. Tattersall: Indian Mysidacea. 459 



state and agrees very closely with Zimmer's figure of the same 

 appendage in A. frontalis. This male specimen does not appear 

 to be quite fully grown. In the proportions of the telson and 

 scale it agrees with A. grossa. A study of my specimens of A. 

 grossa seems to indicate, however, that Zimmer's male of A. fron- 

 talis was not fully grown. Hansen (1910) has given a figure of 

 the distal portion of the exopod of the third pleopod of an 

 immature male of A, grossa which shows a stage earlier in deve- 

 lopment to the one I figure here. I suggest, therefore, that A. 

 frontalis will prove to be founded on not quite adult males of A. 

 grossa 



Distribution. — Waters of the East Indian Archipelago, Bay 

 of Bengal, Gulf of Siam (Hansen, 1910) ; Gilbert Islands (Hansen, 

 1912). 



Zimmer's specimens of A . frontalis were taken during a voy- 

 age from Ceylon to the Dampier Straits, New Guinea and therefore 

 in the same waters as A . grossa. 



Genus Gastrosaccus Norman. 

 Gastrosaccus dunckeri Zimmer. 



Gastrosaccus dunckeri, Zimmer, 1915 (3), p. 165, text-figs. 13-18. 



Locality. — Off Puri Beach, Otissa, 4-4^ fathoms, 57 specimens. 



Remarks* — This species belongs to the same group of species 

 of the genus as G. sanctus and is very closely allied to that species. 

 It is distinguished mainly by the remarkably well-developed lobes 

 on the carapace and the shape and armature of the telson. The 

 lobes on the carapace are larger than in any other species of the 

 genus They extend forward to the centre of the dorsal surface 

 of the carapace and are acutely pointed in shape. 



Distribution. — Zimmer's specimens came from the Duncker 

 collection made during a voyage from Ceylon to New Guinea. 



Gastrosaccus muticus Tattersall. 



Gastrosaccus muticus, Tattersall, 1915, p. 152. text-fig. 1. 



Locality. — Off Puri, Orissa, 4-4^ fathoms, muddy sand. 

 Eight adult females, 7 mm. 



Several localities in the Matlah River, Gangetic Delta, abun- 

 dant. 



Remarks. — There are no male specimens, but from the form and 

 armature of the telson, which in all the specimens has fourteen 

 spines on its lateral margin, and by the possession of a fringe of 

 six to nine filaments on the posterior median dorsal margin of the 

 carapace, I feel certain that these specimens belong to the same 

 species as that which I have described from the Chilka Lake. No 

 other records are known. 



A single mutilated female specimen in this collection from 



