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 retroat, until they are 
strong enough to get their own living. 
For the most part in this Order, liowevor, 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. Rnd Some aiO 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 tiiis Shrimp in "Excelsior, vol. i., p. 229. 
