224 Q-. M. Giles — Six neio AmpMpods from the Bay of Bengal. [No. 2, 



The first three abdominal appendages are subequal and are of quite 

 the usual amphipod type, but are rather short. The three remaining 

 (Fig. 8) abdominal appendages differ greatly in length ; the 1st has 

 the protopodite as long as the basipodite of the longest thoracic append- 

 age ; its two rami are foliaceous, the inner slightly exceeding the outer 

 i^mus. The 5th is but half the size of the 4th, and the irregularity of 

 its rami is more marked, while the last appendage is but half the length 

 of the penultimate and has its inner ramus nearly twice as long as the 

 outer. 



The animal agrees well with all the characteristics of the genus as 

 given in Spence Bate, though the 8th thoracic appendage would perhaps 

 be better described as stunted than as rudimentary. 



§ 4. Lestrigonds bengalensis, n. sp., Pis. VI. & VII. 



In looking over the literature referring to the genera Lestrigonus 

 and Hyperia, it becomes increasingly apparent that Spence Bate's 

 suspicion as to the doubtful value of the latter genus was well founded. 

 One after another species of Lestrigonus have been paired off as males 

 with Hyper ia females, so that the latter genus must, in all probability, be 

 entirely abandoned, as its retention could only be justified by the dis- 

 covery of a form whose males retain permanently the character of the 

 genus. 



The present species is one of the commonest surface organisms of 

 the Bay of Bengal, and is especially so in the more truly pelagic por- 

 tion of its area. 



I was on this account able to obtain a large number of specimens, — 

 including (a) females of Hyperia form, but with rudimentary inferior 

 antennae ; (b) immature males of Hyperia-iovm. ; and (c) 9 mature males 

 of Lestrigonus form, — amongst which all stages between the two latter 

 conditions were observable. 



I notice that the pelagic Lestrigo7ii are very generally credited with 

 being parasitic on medusae, &c. In the present species, this is not 

 the case. I have occasionally seen them ensconced in the cavity of a 

 Salpa, but believe this to have been an accidental circumstance, as by 

 far the larger number were captured swimming freely. 



The specimen figured (PL VI.) was taken in the drift-net about 

 100 miles from land in the Bay of Bengal, the depth of the water in the 

 locality being 850 fathoms. Seven specimens were obtained on this 

 occasion and some hundreds have since been taken. 



As all specimens of the Lestrigonus-iovm. are of nearly equal size, 

 and all the appendages are fully developed, it is probable that they are, 

 in spite of their small size, adult animals. The greater part of the 



