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



The liead is small and somewhat excavated below, the antennga 

 originating a good deal behind the antennnles. There is no rostrum, 

 and the single small black rounded eye is placed on a prominent angle 

 situated between the antennnles and antennae. 



The thorax forms a little more than half of the entire body length, 

 and is long and slender, the segments (saving the first, which is shorter) 

 being subequal. The coxal plates are small and narrow, the anterior 

 ones being so short as not to overlap in all positions of the animal ; that 

 of the third is the deepest, while the last three are extremely narrow. 



The ahdomen is small and, like the thorax, narrow, its first three seg- 

 ments being about the same size and depth as the immediately preceding 

 thoracic segments with their coxas. The last three segments are small 

 and nearly cylindrical, and the short telson is armed above with a pair 

 of peculiar conical protuberances bearing a single strong bristle. The 

 last three segments also have their posterior borders furnished, in the 

 middle line, with a few short stiff hairs. 



The antennnles and antennce are stout, approaching the pediform, espe- 

 cially in the case of the latter. They are subequal in length, the anten- 

 nnles being a little the longer, equalling the length of the thorax less its 

 last segment. The peduncle of the antenyiules forms nearly two-thirds of 

 the entire length of the organs and is very stout. It consists of three joints, 

 of which the first is the stoutest, but is intermediate in length between the 

 two remaining joints, the second joint being much the longest and form- 

 ing nearly half the peduncle, while the last joint is the shortest and 

 slenderest. All three joints are moderately hirsute, especially along 

 their inferior borders. The appendage of the antennule is uni-articulate, 

 and so small as to be very easily overlooked, indeed, it is of so delicate a 

 character that it will be found to be wanting in a large proportion of 

 specimens. The flagellum proper is very slender and consists of 10 to 14 

 short articuli armed with extremely short hairs. 



The peduncle of the antennce is both absolutely and relatively much 

 longer and stouter than that of the antennnles. It is five- jointed, the first 

 two joints being short, but very stout, the last two very long and sub- 

 equal to each other and to the long middle joint of the peduncle of the 

 antennule, and the third joint about half the length of the two distal 

 pieces. All its joints are moderately hirsute especially on the inferior 

 borders, and the last joint is additionally armed on the sides with 

 a number of stout tooth-like spines. The flagellum is very short, 

 forming not a quarter of the entire length of the organs, and consists of 

 10 or 12 very short, feebly armed articuli. 



The gnathites and the digestive apparatus generally present a strono- 

 general resemblance to those of Ampelisca lepta, already described. The 



