ON CRUSTACEA. 287 



sion would indicate, or rather clearly announce, that Aristotle 

 had not himself observed the fact which he relates, or that he 

 would testify some uncertainty on the point. 



Pliny has confounded, under the common name of pin- . 

 notheres, thepaguri, and the species of our genus pinnotheres, 

 properly so called. 



We must not apply, as some authors have done, to these 

 last Crustacea, a passage of Appian, in his Halieutics, in 

 which he relates that the crab, when the oyster comes to open 

 its shell, puts a stone between the two valves, so that it cannot 

 close, and he thus penetrates into it with facility, and devours 

 its inhabitant. In another passage, which directly concerns 

 the pinnotheres, Appian does not explain himself respecting 

 the habits of these animals, in a manner different from that of 

 his predecessors. 



Hasselquist, in his voyage to the Levant, says, respecting 

 his pinna muricata, that the cuttle-fish is the most irrecon- 

 cileable enemy of the molluscum, which inhabits this shell. 

 But, happily for it, there are always inside, one^ or several 

 crab-fish, which remain at the entrance of the shell when the 

 animal opens it, and give warning to it to close on the ap- 

 proach of the cuttle-fish. " Thus," continues he, " the pinna 

 permits, in compensation, the crab to reside within its shell." 

 We may well believe that this crustaceum has no need of such 

 permission to establish itself there, and that the quick move- 

 ments which it makes to withdraw itself from the danger by 

 which it is also threatened, are sufiicientto frighten the animal 

 of the pinna, and induce it to keep its shell close. This crab- 

 fish of Hasselquist is probably a species of salicoque, {cari- 

 dion) or pinnophylax, considered in the same light as the 

 ancients considered it. Linnaeus, after the authority of his 

 disci])le, but from very vague information, at first ranged this 

 crustaceum in his division of cancri macroiiri, but subse- 

 quently, whether he wished to omit it as a species too uncer- 



