1922.] W. M. Tattersai.l : Indian Mysidacea. 461 



species as G. sanctns and is very closely allied to that species. It 

 will be best to refer to Sars' description and figures of G. sanclus 

 (1877) and to point out the differences between the two forms. 



G. kempi agrees with G. sanctus in general form and in the 

 details of the appendages of the head and thorax but differs in the 

 following points : — 



(1) There are no lobes or lappets on the dorsal hinder margin 

 of the carapace. 



(2) The antennal scale is slightly more than three times as 

 long as broad, the terminal spine on the outer margin not quite 

 extending as far forward as the apex of the terminal lobe. A 

 suture across the terminal lobe is present. 



(3) There are fifteen marginal spines on the outer uropod and 

 fourteen spines on the inner lower margin of the inner uropod. 



(4) Telson somewhat less than two and a half times as long as 

 broad, cleft about one eighth of the total length, eight spines on 

 each lateral margin, the terminal spines about one-sixth of the total 

 length of the telson, about 3-5 small spinules between the spines of 

 the lateral margin from the third to the eighth {terminal) spine. This 

 last character is unique in the genus. 



(5) First, fourth and fifth pleopods of the male exactly as in 

 G. sanctus. Second pair with the endopod composed of seven 

 joints, exopod of eight joints, half as long again as the endopod, 

 slightly curved, the proximal joints armed with peculiar plumose 

 setae. Third pair wrth the endopod six-jointed, not as long as the 

 first joint of the exopod. Latter very elongate, with the terminal 

 spines extending to the base of the telson, four-jointed, the second 

 and fourth joints each longer than the third, fourth joint termina- 

 ted by a long feathered spine, almost as long as the joint, and 

 a small simple spine. 



The form and spinulation of the telson will serve to distin- 

 guish this species from any hitherto described. I know of no other 

 species which has subsidiary spinules between the large spines 

 arming the margin of the telson. Otherwise it agrees closely with 

 G. sanctus except for the absence of lobes on the carapace and 

 minor details in the number of spines on the telson and uropods. 



Gastrosaccus pacificus Hansen. 

 Text-figs. 8a, b. 



Gastrosaccus pacificus, Hansen, 1912, p. 198, pi. 2, figs. 2,a-g. 



Locality. — Port Blair, Andaman Islands. 

 St. 3. Five males, four females. 

 St. 7. Two males, one female. 

 St. 32. One male. 



