68 



THE WALKS ABROAD OF 



To this belong snails, top -shells or trochi, the cowries, 

 the helmet-shells, and the buccini or Triton's shells. 

 It is in this group that we find the mollusca of 

 greatest beauty and most varied forms. Lastly, the 



Murex. 



JIaliotis. 



GASTEEOPOD MOLIAJSCA. 



Acephala,* or if you prefer it, the molluscs that have 



no head." 



" Animals without a head ! How absurd." 



" I am not joking. Have you ever seen the head 



of a mussel or of an oyster ? " 



" You are right," said the Parisian, a little abashed 



at his own boldness, "but I admit this did not occur 



* The name Acephala has suffered many -vicissitudes since the time of 

 Cuvier, and the group of mollusca without heads is now usually termed 

 Lamellibranchiata, or by some Conchifera. 



