152 



RATHBUN 



maxillipeds reach to the end of the antennal peduncle. The chelipeds 

 are unequal, the longer one in the male nearly as long as the body ; 

 setose ; its inner surface and also the outer surface of carpus and manus 

 covered with sharp granules or short spines ; upper margin spinose, also 

 lower inner margin of merus ; lower outer margin of merus outlined with 



very short blunt spines and 

 a single longer distal spine ; 

 lower margins of propo- 

 dus armed with dentiform 

 granules. Margins of pro- 

 podus sub-parallel. Fin- 

 gers shorter than palm in 

 adult males, just as long 

 as palm in smaller males 

 and in females; usually 

 slightly gaping at base; 

 occludent edges finely and 

 irregularly dentate. The 

 stouter cheliped may be 

 longer or shorter than the 

 slenderer one. In the fe- 

 male the chelipeds are two 

 thirds as long as the body. 

 The second pair of feet are 

 a little stouter and shorter 

 than the last three pairs; 

 the first four joints have a 

 few spines on lower mar- 

 gin ; the carpus a few spines 

 toward the distal end ; mar- 

 gins long-setose. Meral 

 joints of third and fourth pairs of legs with an infero-distal spine ; last 

 three pairs more or less setose, especially so on the dactylus and distal 

 end of the propodus. 



Abdomen almost smooth ; there are a few setse on the sides and on 

 the swimming-fan. The pleura behind the first, which is subacute and 

 armed with a spine, are rounded and decrease in length from the second 

 to the fifth, the anterior margin of the third, fourth, and fifth, and lower 

 margin of sixth, being armed with a small spine. Telson subquadrangular, 

 broadly rounded behind, a median groove, a few lateral and one median 

 marginal spine, 2 larger dorsal spines. Inner branch of caudal swim- 



FlG. 91. Ca!astacus yufnyueseriatus. g (X about j). 

 Station 3196. 



