48 THE VOYAGE OF H.M.S. CHALLENGER. 



row of very slender unciliated setae are affixed. These setae, only found in the adult 

 female, successively increase in length from within outwards, and, together with those 

 on the other side, form a broad fan projecting within the marsupial pouch. The basal 

 joint is much longer than the other joints taken together, and exhibits on the lower 

 side a denticulate ridge similar to that on the maxillipeds. At the end this joint bears 

 some strong ciliated setae, and along the outer edge a regular series of bristles. The 

 terminal part apparently consists of but four joints, the ischial joint not being distinctly 

 defined. Of these joints the antepenultimate (carpal) is by far the longest and bears 

 at the outer corner, like the preceding joint, a ciliated seta of moderate length, and 

 along the inner edge a dense row of smaller setae. The penultimate joint is also 

 densely beset with bristles along the inner edge, and has also an unusually strong and 

 elongated seta affixed to the outer edge close to its base. The terminal joint, finally, is 

 quite small, conical in form, and provided with an apical claw-like spine besides some 

 small bristles. 



The second pair of gnathopoda (fig. 6) are much larger, and possess the full number 

 of joints. The basal joint is more than twice as long as the terminal part, and strongly 

 curved. Along the outer half of the inner edge there is a dense series of ciliated 

 bristles, and from the outer slightly projecting corner four very strong anteriorly 

 directed plumose setae arise. On the lower side this joint has a few scattered 

 denticles, and at the inner corner a somewhat stronger dentiform spine. Of the 

 joints composing the terminal part, the penultimate (propodal) is the longest and 

 rather slender, whereas the terminal is quite short and armed at the tip with several 

 curved spines. The exopodite affixed to the basal joint of these limbs scarcely exceeds 

 half the length of this joint, and has the terminal part divided into six setiferous 

 articulations. 



The first pair of legs (fig. 7) are, when fully extended, about as long as the carapace. 

 The basal joint is very large, slightly tapering towards the end, and strongly curved at 

 the middle, with a dense series of ciliated bristles along the outer part of both the outer 

 and inner edges. Moreover, this joint is armed with several strong denticles, somewhat 

 irregularly arranged on the lower side, some of them, however, forming a regular series 

 along an elevated ridge close to the outer edge. Of the joints composing the terminal 

 part, the two first are rather short, whereas the three outer are very slender and almost 

 equal in length, forming with each other strong geniculate bends. The exopodite is 

 somewhat larger than that of the last pair of gnathopoda, and, moreover, differs by the 

 basal part being denticulate and setiferous along the outer edge, and by the terminal 

 part having two additional joints. 



The second pair of legs (fig. 8) do not nearly attain the length of the first pair, and 

 taper rapidly towards the end. The basal joint is scarcely more than half as long as 

 that of the preceding pair, and only slightly curved. It exhibits along the lower side 



