Primitive members of this phylum contain pairs of gills called ctenidia, and the organs of smell in this phylum are known as osphradia. Most members of this phylum contain an 
Primitive members of this phylum contain pairs of gills called ctenidia, and the organs of smell in this phylum are known as osphradia. Most members of this phylum contain an odontophore, which supports a ridged tonguelike structure known as the (*) radula, or the mantle, which is modified into an organ of propulsion in order Cephalopoda but secretes an external shell in most other orders. For 10 points, name this phylum that contains octopi, clams, and snails.
Primitive members of this phylum contain pairs of gills called ctenidia, and the organs of smell in this phylum are known as osphradia.
Mollusca [accept Mollusks]