MOLLUSCA. ot 
mere trinkets on which he looked dotingly, without 
knowing, and scarcely wishing to know, the 
organization of the animal whose skeleton only 
was before him.” * 
In these days, however, the examination of the 
shell is considered by all who possess any claim to 
science, as subordinate to the history of the entire 
animal. 
Naturalists arrange the MoLLusca im six classes, 
named Cephalopoda, Pteropoda, Gasteropoda, 
Conchifera, Brachiopoda, and Tunicata. Of these 
the first three are sometimes distinguished as Hn- 
cephala, or furnished with a head ; the last three as 
Acephala, being destitute of that organ. 
* Penny Cyclop., art. MaLacoLoey. 
