392 



CONCHIFERA. 



among the retractile tentacula placed around its circumference. 

 These, which are represented in the figure of Pecten already 

 given (j#g.l76), are considered by Poli* to be so many distinct 

 eyes thus singu- fig, 132. 



larly situated ; 

 and, from the 

 circumstance of 

 their being fur- 

 nished with so 

 many organs of 

 vision, he applied 

 the name of Argus 

 to the Mollusca 

 possessing them. 

 Should the bril- 

 liant specks in 

 question be really 

 ocelli, they cer- 

 tainly are placed 

 in the only posi- 

 tion where they 

 could have been 

 efficient as instru- 

 ments of sight, 

 inasmuch as the 

 margin of the 

 mantle is, in such 

 animals, the only 

 portion of the 

 body capable of 

 being protruded 

 beyond the boun- 

 daries of the shell 

 to a sufficient dis- 

 tance to allow the 

 creature to peep 

 into the world 

 around it. 



(427.) All the 

 CONCHIFERA are 

 hermaphrodite as relates to the organization of their generative ap- 



* Poll, Testacea utriusque Sicilian, eorumque Historia et Anatome, 3 vols. fol. 



