224 DE. C. CHILTON ON THE SUBTEERANEAN 



the outer margin near the base it bears a single seta; its extremity is marked off into a 

 distinct unguis, at the base of which is a small seta on the inner margin. 



First gvathopod (fig. 20). The coxa (side-plate) is almost rectangular, sloping a little 

 forward, its anterior edge bearing five or six short setse. The basos is narrow at the base, 

 but rapidly widens until it is quite half as broad as long ; its anterior edge is nearly 

 straight and bears a tuft of five long setse near the base and a single seta at the extremity ; 

 the posterior margin is very convex and bears four or five setae, the longest being at the 

 extremity. The ischium is short, broader than long, and bears five or six setae at 

 the extremity of the posterior margin. The meros is rounded distally, and has the 

 whole extremity thickly fringed with long, rather stout setse. The carpus is triangular, 

 extremity nearly straight, with a row of long setse running parallel to it along the 

 posterior half of the inner surface; the short posterior margin densely covered with 

 setae, apparently arranged in three or four transverse rows. The propodos is ovate, about 

 as long as the three preceding joints together, scarcely wider than the carpus ; anterior 

 margin convex, with four or five setae separately situated along the inner surface near 

 it and a small tuft at the base of the dactylos ; posterior margin with numerous setae 

 partially arranged in five or six tufts ; palm oblique, occupying rather more than half 

 the posterior margin, defined by two stout spines and fringed with numerous short 

 setae, a few longer setae being situated on the surface of the propodos near the palm. 

 The dactylos is slightly curved, fitting closely on to the palm ; the terminal uuguis 

 distinct and marked ofi^ by a small tooth on the inner margin at its base ; on the outer 

 margin the dactylos bears a plumose seta at a little distance from the base. 



The second gnatliopod (fig. 21) is aboitt as large as the first and closely resembles it 

 in form. The coxa is similar but someAvhat larger, the basos sli^'htlv lona-er in 

 proportion to its breadth. The carpus much longer than in the first gnathopod, with 

 more numerous tufts of setae on its posterior margin and a shorter row along the 

 extremity. The propodos is like that of the first gnathopod, but the palm does not 

 occupy so much of the posterior margin, and there is a larger number of tufts of setae 

 between the end of the pabn and the base of the posterior margin. 



In both gnathopoda the outer surface bears fewer setae than the inner. 



The first pera'opod (fig. 22) has the coxa like that of the second gnathopod. The 

 basos is longer, and widens considerably about the middle, where the breadth is rather 

 more than one-third the length ; it is much constricted on both sides near the base, and 

 after widening narrows again slightly at the extremity ; the anterior margin bears a 

 few small setae, and the posterior margin bears six stout setae, each situated in a slight 

 serration. The ischium is similar to that of tlie second gnathopod. The meros is 

 slightly longer than the carpus, and is a little produced at the antero-distal angle ; the 

 anterior margin slightly convex, and bearing one spiniform seta at the centre and 

 another at the extremity ; posterior margin straight, with a few long setae, the longest 

 two being at the extremity. The carpus is oblong, narrowed at the base; anterior 

 margin with one or two minute spinules ; posterior margin straight, with five stout 

 setse. The propodos is shorter and narrower than the carpus but of similar shape ; 

 posterior margin with a row of six or seven short setse, the last being the longest; 



