CRABS AND SHRIMPS, 217 



For the protection of the eggs in this genus there is a 

 peculiar provision. They are proportionally large and 

 few in number, and, when laid by the mother, are not 

 committed to the free element, but are deposited in a sort 

 of chamber between the valves of the shell, above the 

 animal's back. Here they are carried until the young are 

 hatched ; and even for some days more the little ones 

 avail themselves of the same safe retreat, until they are 

 strong enough to get their own living. 



For the most part in this Order, however, the eggs are 

 excluded in two large oval bags, which hang behind the 

 parent, one on each side, these bags (external ovaries) 

 being frequently each as large as the whole animal. 

 When matured the young escape, and the sacs slough 

 away, to be soon replaced by a new pair. 



Some of this race are 

 not enclosed in shells : 

 the genus just alluded to 

 (Cyclops) and its fellows 

 have the upper parts pro- 

 tected by a large buckler 

 and hollow horny rings, 

 much like the armour of 

 the Shrimp and Lobster, 



Cyclops— in its young and mature states. and some are deprived of 



everything answering to a shield. Of the latter sort, 

 which is, however, the exception to the general rule, is 

 the Brine-shrimp (Artemia salina), which delights in the 

 intensely salt pits of salt-works, as at Lymington, and 

 elsewhere.'* 



* See an interesting account of this Shrimp in " Excelsior," vol. \., p. 229. 



