HALF AN HOUR WITH CRUSTACEA. 253 



between the eyes, called the rostrum, and in Paltemon 

 serratus (Fig. 137) this is notched like a saw, whence 

 the name. The latter attains a length of four inches, 



Fig. 137. 



Palsemon serratus. 

 Fig. 138. 



Palcemon squilla. 



and it is when young that it gets mistaken for the 

 shrimp. The squilla (Fig. 138) is smaller, and 

 perhaps has to suffer even more through the same 



