150 FUNAFUTI ATOLL. 



sixth and seventh legs, have a bead-shaped elevation on the 

 posterior surface a little below the middle ; third joints shorter 

 than the second, and in all the legs more or less produced and 

 lobate at the infero-distal extremities ; fourth joints short, the 

 fifth bent over and opposable to the distal lobe of the third joint, 

 sixth joint minute, triangular, and opposed to a projection of the 

 propodus. 



The first and second segments of the pleon are as long but not 

 quite so broad as the last segment of the perseon, the fourth is 

 about half the size of the third, fifth and sixth very short and 

 subcylindrical, the latter terminating abruptly, and bearing a 

 pair of minute lanceolate appendages. 



The pleopoda are inserted on the margins of the pleon. They 

 are pedunculate and consist of sixteen foliate plates ; the first 

 joint is about twice as long as broad, the outer and inner rami 

 are situated at its distal extremity, the inner ramus is obovate 

 and almost sessile, the outer with a peduncle as long or longer 

 than the basal joint, the lamina is subfalcate with an even curve 

 on the outer margin, its inner straight distally and lobate proxi- 

 mally ; the fourth outer ramus is a little shorter than the 

 perseon. 



The first pair of marsupial plates is folded in front of the 

 head so as to produce a kind of funnel, consisting of two spout- 

 shaped lobes ; posteriorly on the ventral surface they are pro- 

 duced and form a pair of subfalcate blades, which are evidently 

 of a vibratory character and seem well adapted to drive a current 

 of water through the brood pouch. 



There are five pairs of functional marsupial plates, the second 

 pair overlaps the falcate prolongations of the first pair, the 

 posterior ciliate margins of the last and largest pair do not 

 extend beyond the terminal segment of the perseon. 



The colour of the peneon above and below, and of the lower 

 surface of the pleon is light salmon yellow, the legs and the 

 peduncles of the pleopods are yellowish-white, the pleopodal rami 

 are opaque-white, with a few translucent lines radiating from the 

 midrib ; the anterior and posterior marsupial plates are somewhat 

 opaque, the intermediate plates are translucent. 



As the specific name implies, the host of this Epicarid is 

 Aniculus typictis, which hermit crab invariably occupied the 

 shell of Turbo setosus, Gmelin, and was never seen except at low 

 water, on the edge of the outer reef most exposed to the surf, 

 where it was rather rare. This most interesting parasite the 

 only one procured by the Expedition was accidently discovered 

 on the anterior surface of the abdomen, near the hinder margin 

 of the carapace. The host was drowned in fresh water, and 

 when dead was found somewhat exserted from its shell, exposing 



