ANIMAL KINGDOM. 245 



He is himself even unable to give any satisfactory reason 

 for this last innovation ; for surely it is contrary to the first 

 principles of Natural History, to admit that the bisection 

 of a class can be otherwise than artificial, when it is 

 almost entirely founded on the idea that the group, as it 

 previously existed, w^as too numerous. As to Lamarck's 

 Heteropoda, it can only at present be said, that Cuvier^ 

 whose opinion was founded on anatomical examination, 

 considered them as Gasteropoda, and that the characters 

 given to th'.s proposed class by its author, who by the by 

 appears only to have judged from their external appear- 

 ance, are not sufficient to separate them from the Ptero- 

 poda. 



A well known British NaturaUst, who has paid more 

 attention than any person in this countiy to the anatomy 

 of the Mollusca, and whose observations on the subject 

 are at this moment anxiously expected, will without doubt 

 remove the obstacles which the natural arrangement of the 

 Mollusca has hitherto had to encounter, and will place the 

 science on a basis Avhich Avill tend to make it of as much 

 use to the general Zoologist, as to the many persons in 

 England who cultivate Conchology alone. I shall there- 

 fore merely once more acknowledge, that what I have said 

 of the Mollusca is an imperfect and hasty attempt to re- 

 concile Cuvier's observations, as far as it was possible, with 

 the existence of facts which I had previously reason to 

 suspect from other considerations, and I shall now proceed 

 to characterize generally this very peculiar group of or- 

 ganized beings. 



The Mollusca are soft inarticular animals, breathing by 

 branchiae, or lungs, which vary in form and situation. 

 They are moreover possessed of a complete system of cir- 



