1900.] FROM THE FALKLAND ISLANDS. 551 



6-jointed, shorter than peduncle of second, first joint nearly as 

 broad as long, second shorter and much narrower, third about half 

 as long as second ; flagellum small, its middle joint longest. 



Second antennae apparently with a minute rudiment of a 

 process on the third joint, carrying 2 spinules, sixth joint of 

 peduncle a little longer than 5th ; flagellum sometimes nearly 

 twice as long as peduncle, attaining to 25 joints (20-30 are given 

 for I. harc/eri). 



Upper lip with rounded or somewhat flattened apical margin. 



Under lip with rather strong setules on the obtuse apices. 



First maxillae. — Inner plate not linear, its margins convex, the 

 apex carrying 4—5 setae ; outer plate much broader, apex fringed 

 with 11 spines in two series. 



Second maxillae. — Inner plate moderately broad, with numerous 

 setae on apex ; outer plates narrow, each with 4 apical setae, longer 

 than those on inner plate. 



Maxillipeds. — First joint short, the epipod irregularly oblong or 

 oval, not reaching beyond first joint of the palp ; second joint broad, 

 its terminal plate nearly as long as the base and more than half 

 as broad, with one or two coupling spines on inner margin, and 

 several spinules fringing the apex; first joint of palp short, second 

 rather broad, scarcely longer than broad, third much shorter and 

 narrower, distally narrowed, fourth as long as second but narrower 

 even than third, fifth much shorter than fourth. 



Limbs of peraeon all nearly alike. First pair (gnathopods) are 

 a little shorter than the others, and, so far as I could discern, are 

 "without the triangular prolongation of the sixth joint seen on the 

 other pairs. In all, the second joint is little broader than the 

 fifth and little longer than the sixth, the fourth is shorter than 

 the third, the fifth is decidedly broader than the sixth, but scarcely 

 so long. The short finger has a broadly oval base, from which 

 issues a strongly curved nail on the outer side of the apex, and 

 on the inner side two similar but shorter nails ; between these and 

 the longer nail a curved spine may sometimes be seen protruding. 

 The two smaller nails are placed so close together that they often 

 look like a single two-pointed nail. Over the broad part of the 

 finger the apex of the sixth joint is produced in a triangular process. 



In the female, the operculum of the pleon is broadly rounded, 

 with a produced obtuse apical point. 



The uropods are rather more (or slightly less, Bovallius) than a 

 fourth of the caudal shield. The outer ramus is as long as the 

 peduncle, and has several setae on the truncate but narrowed apex, 

 with one or two setules near the middle ; the inner has a basal 

 part as long as, but broader than, the outer, with a narrower and 

 much shorter apical portion, separated as it were by a fringe of 

 spinules and tipped with long setae. 



The specimens Avere of various sizes (including young with the 

 seventh pair of trunk-legs undeveloped). All the adults seemed 

 to be females, the largest scarcely exceeding 2*5 mm. 



Locality. Falkland Islands. On Exovphceroma yiyas. 



