386 Dr. C. Chilton on 



seems to me to be quite as unguiform as in most of the 

 specimens of L. lignorum that I have examined. 



A comparison of the uropoda of the species at my disposal 

 shows that the structure is essentially tiie same throughout 

 and that the resemblances are very close, closer than might 

 be anticipated from a comparison of the figures given b}'' 

 different authors. In all three the peduncle bears on tlie 

 under surface, at some little distance from the outer margin, 

 a longitudinal row of long, finely plumose hairs; other hairs 

 of more unequal length fringe the actual margin. The end, 

 of the peduncle is produced on the underside into a small 

 subacute triangular process between the bases of the rami. 

 The inner ramus is much the longer and bears at the 

 extremity, which is usually truncate, a tuft of long seta?, 

 about as long as the ramus itself; other seta) may be present 

 on the outer margin, but the inner margin seems in all cases 

 almost free from setse. The inner ramus is short : it curves 

 outwards and ends in a nail, at the base of which, on the 

 concave side, is a tuft of about three setse which reach beyond 

 the end of the nail. 



In L. h'gnorum the outer margin of the peduncle usually 

 bears a number of small tubercles or small blunt spines. I 

 have, however, failed to find these in some of the Auckland 

 specimens, in which the outer margin is slightly roughened 

 only; in these specimens tlie uropod is hardly distinguishable 

 from that oi L. segnis (compare tigs. 5 and 7). 



In the specimens from South Georgia, which, I have no 

 doubt, must be referred to L. antarctica, Pfeffer, the outer 

 margin of the peduncle (fig. 8) shows slight evidence of 

 tuberculation : both rami are short, though not quite so short 

 as is shown in Pfeffer's figure, taken from South Georgia 

 specimens, and in one specimen, a small one, it has a nail at 

 the end quite similar to that in L. lignorum, though smaller. 

 In L. pfejftri the figure given by Stebbing shows that the 

 jjeduncle is the same as that in L. lignorum or L. segnis, and 

 it is probable that the whole uropod of L. pfefferi is practi- 

 cally the same as in these two species. The uropoda of 

 L. andrewsi, as drawn by (Salman, have a short peduncle and 

 look rather ditferent from those of the other si)ecies, but his 

 figure is too small to shmv the details referred to above. 



From the foregoing account it will be seen that there is a 

 very great resemblance between all the species, both in 

 general appearance and also in more minute characters of the 

 various aj)pendages ; they constitute a well-marked genus, 

 which occupies an isolated position under the Spha3romida3. 



