SCALPELLUM. 



Crustacea. Mr. Thompson in his Zoological Researches, 

 announces the discovery that they are truly Crustacea. 

 Without describing the facts or entering upon the argu- 

 ments with which he supports this opinion, we must be 

 permitted to say, that we do not think that he has fully de- 

 monstrated it; at the same time, considering that as far as 

 we hitherto knew, the Cirripedes were all attached, the cir- 

 cumstance of their being free when very young, accounts 

 well to our mind for the fact of each species being found 

 attached to peculiar situations, which would only be com- 

 patible with the notion of their being at one time free 

 agents, and possessed of an instinctive volition determining 

 their choice of situation. 



