246 G. M. Giles — Notes on the Amphipoda of Indimi Waters. [No. 3, 



appendages, being as long as the head and first five thoracic segments, 

 while the eighth is a trifle shorter, and the sixth is only subequal to the 

 second gnathopod. 



The three anterior abdominal appendages are of the nsual type and 

 are strong and well developed. The last three appendages are strong, 

 with the inner ramus slightly shorter than the outer, both rami being 

 armed with stoutish spinous hairs. The three pairs of rami are 

 subequal, but the peduncles differ a good deal in size, that of the fifth 

 being only half, and that of the sixth only a quarter, the length of the 

 peduncle of the fourth. 



Our species differs from the hitherto described members of the 

 genus as below : from A. gibhosus, A. bispinosus, A. swammerdamii, 

 A. villosus, A. carinatus, A. corallinus, A. huxleyanus, A. spinuUcauday 

 and A. compressus, in having no dorsal carinse or spines ; from A. 

 crenulatus and A. austrinus in having the antennee subequal, and not 

 differing considerably in length as in those species ; from A, vulgaris 

 and A. capensis in the antennse being considerably shorter ; and from 

 A. inermis, A. simplex, and A. jissicauda in the last three thoracic 

 appendages not being subequal, bat differing a good deal in length. 



8. Urothoe ruber, n. sp., PI. XI. 



This form was extremely common in the surface net takings on the 

 banks of Chittagong, and was easily distinguished from the other organ- 

 isms comprised in the catch by its bright brick red colour. Its length 

 is about 3 mm. 



Its liead is small and somewhat olive-shaped ; the large eyes being 

 placed rather high up on its lateral aspect. 



The thorax is of moderate size, forming rather less than half of the 

 body length, excluding the head. It is depressed rather than com- 

 pressed and its segments increase in size regularly from before back- 

 wards. The coxal plates are deep, especially the first four ; owing to 

 their extreme transparency it was difficult to make out the posterior 

 ones clearly, but they appeared to be as in the figure, the 5th not being 

 markedly small, as indicated in the generic diagnosis ; this, however, 

 is also the case in U. elegans (Sp. Bate). 



The abdomen is large, forming nearly half of the entire body 

 length, its 3rd segment being the largest and alone as long as the head, 

 while the 5th is the shortest of all. 



The antennule is small, its peduncle is three-jointed and as long as 

 the head, and its basal joint is armed dorsally with a number of plumose 

 compound hairs. The flagellum is very small, 4-jointed, and its ap- 

 pendage even smaller and made up of two very slender articuli. 



