OiV CRUSTACEA. 305 



upon this genus, a name by which the ancients designated a 

 sort of crab, or one of the brachyurous Crustacea. The in- 

 habitants of the maritime coasts of France, who are also ac- 

 quainted with the habit which these animals have of enclosing 

 themselves in univalve shells which they find empty, call 

 them hermits^ or soldiers, because they compare this shell, 

 which serves them as a dwelling, to the cell of a hermit, or the 

 sentry-box of a soldier. Linngeus placed them in the genus 

 cancer, but they have been ascertained strictly to belong to 

 the macrourous decapods. 



Aristotle had already mentioned the fact, that the shell 

 serving as an habitation to the carcinion, or pagurus, was not 

 of its own formation ; that it had possessed itself of it after the 

 death of the molluscous animal which had formed it; and that 

 its body was not adherent to it, as is that of the last mentioned 

 animal. Belon, Rondelet, and many other naturalists, had 

 confirmed these facts ; Swammerdam has, nevertheless, pre- 

 tended, contrary to so many and such well founded authori- 

 ties, that the pagurus was born with its shell, and that it even 

 possessed the faculty of enlarging it, in proportion to its own 

 growth. It is positively known, that on its issuing from the 

 eg^, its body is naked or without a shell ; that its form does 

 not then essentially differ from that which it presents in the 

 adult state ; and, finally, that it is without the mantle and the 

 secretory organ, which nature has accorded to the mollusca for 

 the formation of their shells. 



It has also been falsely advanced, that the pagurus puts to 

 death the natural proprietor of the shell in which it is de- 

 sirous of establishing itself. It only takes possession of one 

 that is empty; and that the posterior extremity of its body 

 may fasten there, it always selects one, the summit of which 

 finishes in a spiral. It is but once a year, at the period 

 of moulting, that, its body, having increased in bulk so as 

 to be too much confined in its domicile, it is obliged to 



VOL. XIII. X 



