JFBESHWATER PRAWNS. 



329 



are terminated by great chelse, not unlike those of the 

 crayfishes. Hence these fluviatile prawns (known in 

 many places bj' the name of " Cammarons ") are not 

 unfrequently confounded with true crayfishes ; thou).'h 



Fig. 79. Palmmon jamaioennU (about f nat. size). A, female; 

 B, fifth thoracic appendage of male. 



the fact that there are only three pair of ordinary legs 

 behind the largest, forceps-hke pair, is sufficient at once 

 to distinguish them from any of the Astacidce. 



Species of these large - clawed prawns live in the 



