MALACOZOA. MOLLUSCA. 



Soft, symmetrical, inarticulated animals; enveloped 

 in a muscular skin or mantle, which generally has 

 attached to it, externally or internally, a calcareous 

 part or shell, of one or several pieces ; and hav- 

 ing a complete douhle circulation, with white 

 blood ; branchial or puhnonic respii'ation ; an in- 

 testinal canal ^vith two apertures ; a nei^ous system 

 composed of a cerebriform ganglion, placed under 

 or surrounding the oesophagus, and communicating 

 with the gangha of the various functions ; those 

 subservient to locomotion being lateral. 



MaXcLKLa and 'OarpaKohep^a, Aristotle, MoUia and 

 Testacea, Pliny. Vermes^ Ray, Linnaeus, Pennant. 

 MoIIusca, Cuvier. Malacozoa, Blainville. MaXaxos-, soft ; 

 Zoiov, animal. 



