1887.] G. M. Giles — Six new Amphipods from the Bay of Bengal. 22l 



though with no great speed. Its most salient peculiarity is the immense 

 length of the rigid 5-jointed antennae, which are much longer than in 

 any form hitherto described, and are carried folded up and directed 

 obliquely downwards and forwards in front of it. 



The total length of the body is 6'5 mm., and the animal is opaque, 

 of a pale pinkish brown tint, and plentifully sprinkled with deep mad- 

 der-brown pigment spots, which are most numerous on the pleura and 

 coxae of the thorax, and on the entire surface of the 2nd and 3rd 

 abdominal segments. 



It is stoutly built, not markedly compressed. 



The head is large, its length, depth, and breadth each equalling 

 rather less than ^th the body length ; its entire upper and lateral 

 surfaces occupied by the large regularly faceted eyes, and its anterior 

 inferior aspect deeply hollowed for the reception of the antennules and 

 of the first joint of the antennae. 



The thorax forms the broadest and deepest part of the body, but its 

 segments are short, so that its entire length is but fth longer than 

 the head. The coxal plates are united to the pleura, without any very 

 obvious suture, and the first and the last two segments have their 

 terga ankylosed. 



The antenncd and antennules are formed on almost exactly the same 

 plan as those of Bhahdosoma. On looking at the latter genus, one is in- 

 clined to be led to the conclusion that the curious antennae have been 

 evolved to enable the animal to reach out beyond the enormously pro- 

 longed rostrum and cephalon generally, which latter formation together 

 with its generally slender form certainly suits the attainment of a high 

 rate of speed. The present species, however, demonstrates the danger of 

 such hasty deduction, as we have here the antennae of even greater 

 proportional length than in Bhahdosoma, while the head and body 

 generally are short and stout and the entire plan of its structure is 

 adapted for strength rather than speed. 



The antennules, when at rest, are almost completely hidden within 

 the depression of the antero-inferior face of the cephalon, the tip 

 of the flagellum only being visible ; they consist of a three-jointed 

 peduncle of peculiar form (Fig. 2.) and a three-jointed flagellum (Figs. 2. 

 & 3.). The basal joint is articulated to the recessed surface of the 

 cephalon, close to the middle line, at a point about even with the 

 middle of the eye. The first two joints are short and compressed 

 and quadrate, directed obliquely downwards and forwards ; the third 

 joint is much larger, and is much compressed, so that, seen from 

 below, it appears merely slightly clavate, viewed laterally, it is seen 

 to be broad and of falciform outline, curving round, so that its distal 



