160 



transverse, and bears four or five setaB at the outer distal angle 

 and two others at the inner distal angle. The meros is subtri- 

 angular, having the outer angle produced nearly to the end of the 

 carpus, while the inner edge is only as long as that of the isehios; 

 the inner distal angle is rounded and bears about 6 or 7 setae, the 

 outer distal portion of the joint is somewhat concave for the 

 reception of the carpus, and has the margin fringed with long 

 setse. The Garj)us is somewhat sunk in the meros, it is narrowed 

 at the base but widens distally and has the end truncate ; the 

 inner margin is densely fringed with two or three irregular rows 

 of setie and there is a small tuft at the outer distal angle. The 

 propodos is elliptical, widest towards the distal end ; the inner 

 margin, like that of the carpus, is fringed with sette, the outer 

 margin bears six long seta? towards the distal end. The dactylos 

 is broad and elliptical and arises from a slight concavity at the 

 end of the propodos ; the whole of the inner margin and the distal 

 half of the outer margin are fringed with long setie, those at the 

 apex: being the longest and also the stoutest. 



From the description given above it will be seen that the max- 

 illipedes of Phreatoicus bear a close general resemblance to those 

 of Asellus aqtoaticus. 



Thejii'st thoracic leg {ov first ynatJiopod). (Plate xxiv., tigs. 5 

 and 5a.) — This appendage has the dactylos bent back upon the en- 

 larged propodos so as to form a powerful subchelate hand similar 

 to that found in many Amphipoda. This form of limb is not so 

 common among the Isupoda, but is found in several genera such as 

 Antliura, Asellus ttc. The basos is strong, about two and a half times 

 as long as the greatest breadth, somewhat constricted near the base; 

 on the anterior margin is a row of 5 or 6 long simple seta?, and 

 there is a tuft of similar setje at tlie postero-distal angle. The 

 isehios is rather more than half as long as the basos, and is sub- 

 rectangular, slightly narrowed proximally; there is a tuft of long 

 simjjle seta? about the middle of the anterior margin and two 

 smaller tufts on the posterior margin. The meros is subtriangular 

 and is produced anteriorly and distally into a rounded lobe 

 partially surrounding the carpus and fringed all round with long 

 simple sette, it also bears a tuft on the posterior margin. The 

 carpics is also subtriangular and has the posterior margin supplied 

 with a fringe of long sette, sometimes indistinctly separated into 

 two tufts, the junction of the carpus with the propodos is oblique. 

 The p7'opodos is very large and ovate, the anterior margin strongly 

 convex with a small tuft of seta? at the base of the dactylos and 

 another placed more proximally ; the palm is oblique, somewhat 

 convex and occupies about two-thirds of the posterior margin but 

 is not clearly defined ; it is armed with a row of stout and very 

 acute spiniform setaj, and also bears a row of long simple seta?, 

 three or four tufts of setse are situated on the surface of the pro- 

 podos near the palm. The dactylos is stout and tits closely on to 



