168 LIFE BY THE SEASHORE. 



it ends. Beneath there are no teeth. The two species show 

 very, little resemblance to one another. The other species 

 of Hippolyte being mostly rare or inhabitants of deep water 

 are beyond our scope. 



Very little observation will convince the student that the 

 three genera just described resemble one another very 

 closely, and no difficulty will be found. in drawing up a list 

 of their common characters. All differ somewhat markedly 

 from the next genus we have to consider that which 

 includes the common shrimp (Crangon vulgaris). Of this 

 abundant and familiar form it is always easy to obtain 

 specimens. In the tidal streams flowing between the rocks, 

 near the mouths of rivers, in sandy pools, wherever there is 

 abundant sand one may be almost sure of finding this 

 ubiquitous form, darting rapidly hither and thither, or 

 burying itself deep in the sand. In life, as everyone knows, 

 shrimps are sand-coloured, but examination with a lens will 

 show you that although the general tint be dull, the shrimp 

 is minutely speckled with brilliant red-brown spots of singu- 

 larly beautiful shape. When boiled, the true shrimp does 

 not become bright red, as do many of its allies, but merely 

 pinkish brown, and on this account is often called the 

 brown shrimp as a distinction from the prawns. The 

 common shrimp is the only species of its genus which can 

 be justly described as common on our shores, but as other 

 species do occur, especially on the West, we may take the 

 characters of the genus first, before mentioning those 

 peculiar to C. vulgaris. All the true shrimps differ from 

 the prawns in the following characters : the carapace is 

 somewhat depressed instead of being flattened from side to 

 side, and the rostrum is rudimentary ; the abdomen is long 

 and very strong; the antennae are placed at the outer side of 

 the antennules, and not beneath them ; the antennal scale is 

 large, and the filaments of the antennules similar. The 

 legs are peculiar, especially the first pair, which are short 

 and stout, and exhibit the condition described as sub- 

 chelate. It will have been noticed that when hitherto 

 appendages have been described as ending in chelae, or 

 forceps, the chela3 have all been of the same structure. 

 That is to say, in each case the last joint ("movable 

 finger") has worked against an immovable prolongation of 



