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 ; thecarpus a fewspines 
Fic. 91. Calastacus guingueseriatus. § (X about 3). toward the distal end ; mays 
Stshon\srge: 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 sete 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- 

