Mollusca
Molluscs have such a varied range of body structures that it is difficult to find defining characteristics that apply to all modern groups. The two most universal features are a mantle with a significant cavity used for breathing and excretion, and the structure of the nervous system.
Cephalopoda
Bivalvia
Gastropoda
Aplacophora
Caudofoveata
Monoplacophora
Polyplacophora
Scaphopoda
Cephalopoda
Bivalvia
Gastropoda
Aplacophora
Caudofoveata
Monoplacophora
Polyplacophora
Scaphopoda