OX CRUSTACEA. 
273 
deposition, for a greater or less time. In some they are fixed 
to the false feet by means of filaments, which result from the 
solidification of the mucus that surrounded them at the 
moment of their issuing forth ; in others, they are placed in 
external membranaceous sacs, or in a dorsal cavity. 
In most species of Crustacea, when the little ones are dis- 
closed, they remain some days near the mother, and place 
themselves under her tail, as has been observed in some crabs, 
and in the river craw-fish, or between the leaflets of the gills, 
as has been remarked in regard to the onisci. 
Most Crustacea are used by us as food. The larger and 
middle sized species, of which the individuals are numerous, 
are those which are in most request. Their flesh is nourish- 
ing, but difficult of digestion, and much of it cannot be eaten 
with impunity. 
The decapod Crustacea are the only animals of this class 
which are eaten in Europe. Among the brachyuri, the most 
esteemed are cancer pagurus , cancer puber , and the maia 
squinado . As to the C. mamas , it is not so much in request, 
and its most frequent use is as a bait to catch fish and other 
Crustacea. Among the macrouri, the palinurus and the lobster 
hold the first rank in consequence of their size, and then come 
palcemon penceus , many species of nika , the river craw-fish, 
and crangon. These last, which are eaten very much, though 
more on the continent than in England, arc also employed as 
bait. 
Many of these Crustacea, such as penams and Palcemon , are 
salted in some parts of the coast of the Mediterranean, and 
sent into the East, where the Greeks make an abundant use 
of them, especially in the season of Lent. 
Formerly the trade in the stones which are found in the 
stomach of craw-fish, vulgarly called crabs ’ eyes , was suf- 
ficiently productive, when these bodies were made use of in 
medicine as absorbents, and it was particularly from Hungary, 
VOL. XIII. t 
