i8o 



E. A. ANDREWS. 



pair of sperm-pockets : each female possessing but one of a 

 symmetrical pair, while its mirror image is to be found upon 

 some other female. 



The sperm-pocket of this species of crayfish, representing 

 the subgenus Procambarus, is thus fundamentally identical with 

 the sperm-pockets in all the other Cambari, thus far studied. 



Turning now to the only specimen of the subgenus Para- 

 cambarus as yet examined with reference to the sperm-pocket 



FIG. 9. Ventral view of annulus and neighboring organs of female 

 45 mm. long, 2a . 



within the annulus we find the general appearances indicated 

 in Fig. 9. The annulus itself is not so remarkable but the 

 spine between the fifth legs attains a height not elsewhere 

 known. The figure shows the bases of the second to fifth legs 

 inclusive and the grooved sternal mass that ends between the 

 fourth legs with flaring wing plates and a concave middle plate. 

 In the concavity so formed lies the annulus, which differs from 

 the usual form chiefly in rising up rather more in the middle 



