ORDER CRUSTACEA HKTEROBRANCHLE. 149 



At the place where the head is united to the body, a 

 small black point is seen, — this is the eye of the 

 animal. 





Cyprli pubcra. (Fig. 1, highly magnified ; fig. 2, natural size.) 



TheCypris changes its shell like the rest of the Crus- 

 tacea; it is found in marshes where vegetable substances 

 are growing. Sometimes they are so numerous, that 

 the water appears covered with them ; they are more 

 usually found in Spring and Autumn than at any other 

 part of the year ; from this it is inferred that there are 

 two broods in the course of the year. 



The drying up of marshes during the Summer heats, 

 destroys immense numbers every season. It appears, 

 however, from observation, that in this case, some of 

 these tiny creatures manage to bury themselves in the 

 mud, where they hermetically close their shells, and 

 remain in a kind of dormant state, until rain or other 

 causes have again filled the marshes with water. 



A species nearly allied to this, the Artemia Salina, 

 the| Lymington shrimp, or brine-worm, is able to live 

 in the brine of the salt-pans, which is so strongly 

 impregnated with salt, as to destroy any other Crus- 

 taceous animal. 



