236 G. M. Giles — Notes on the Amphipoda of Indian Waters. [No. 3, 



sides, are occupied by the eyes, which blend in the middle line so as to 

 appear to be a single organ. 



Tlie thorax is small, forming only a third of the whole body length. 

 The segments increase gradually in length from before backwards, the 

 last being nearly double the length of the first, and are of very moderate 

 depth. The coxal plates, however, are very deep, nearly equalling, as 

 a general rule, the depth of their corresponding segments. The last 

 coxal plate is the only marked exception to this rule, being only half the 

 depth of the corresponding segment and little more than half the depth 

 of that immediately preceding it. 



The abdomen is very large, forming more than half of the total body 

 length, the first three segments alone exceeding the thorax in length, 

 while the remaining three are as long as the first four thoracic segments. 

 The first three segments are of great depth, while the last three are 

 rather narrow. The telson is simple and laminar. 



The antennule is slightly longer than the thorax. It is moderately 

 hirsute, the distinction between peduncle and flagellnm is very ill- 

 marked, the first joint alone of the former markedly exceeding the suc- 

 ceeding articulations in size. The flagellum consists of 10 or 12 short 

 joints. 



The anfennm are slightly longer, exceeding the antennules by the 

 length of an average thoracic segment. The peduncle forms a good deal 

 less than half its length, is moderately hirsute, and consists of fi^e 

 joints, of which the first three are very short and the last two long and 

 stouter than any part of the peduncle of the antennule. The flagellum 

 is very smooth, its hairs being extremely fine and short, and consists of 

 about forty very short joints, the lines between the component articuli 

 being very indistinct. 



With the exception of the maxilliped, which is small, hirsute, and 

 clawed, nothing could be made out of the gnathites, which are very small 

 and almost completely hidden by the sides of the head. 



Tho second and third thoracic appendages are long and slender, the 

 third being a little the longer and stouter, nearly equalling the com- 

 bined head and thorax in length. They closely resemble each other 

 and shew well the peculiar form characteristic of the genus in 

 having the postero-inferior angle of the carpopodite prolonged into 

 a spine opposible to the propodite and long enough to meet the 

 dactylopodite. This spine in the second thoracic appendage pro- 

 jects a little behind the propodite, while in the third the pro- 

 podite slightly exceeds the spine. The fourth and fifth are the 

 shortest of the thoracic appendages ; they are subequal and moderately 

 stout, and closely resemble each other, both being very hirsute and termi- 



