THE BEACH -FLEA. 



We may ohooae either the Gammaras (Fig. 1), ooioted like the 

 heavy maaaea of dark green seaweed under vhioh it hides, or the 

 equally nimble Orchestia, so preoiaely like the sea-aand in its oolor 

 that many a one eacapea from na aa we dig into their holes on the 

 beach. The Gammarua ia the one firat deaoribed in this lesacn. 



Observations to be made : The beach-flea has a very 

 narrow body, strongly carved for jumping. The rings 

 can be seen on the whole of its body except the head. 



FiG.l. 



The last four rings of the abdomen ard narrower and 

 harder than the others. There are seven pairs of legs iu 

 all. Two pairs of these have great claws. There are 

 six pairs of swimmerets. The first three pairs of swim- 

 merets are soft, the others are hard because used iu 

 jumping. There are two pairs of anteanse. The eyes 

 are like two curved black liae^, and are not on stalks. 



An interesting comparison may be made between the 

 shape of the body of Gammarus and that of Orchestia. 

 The former has so narrow a body that it cannot stand 



76 



