Mollusks are triploblastic protostomes. The principal body cavity is a blood-filled hemocoel. They have a true coelom (eucoelom); any coelomic cavities have been reduced to vestiges around the hearts, gonads, and metanephridia (kidney-like organs). The body is often divided into a head, with eyes or tentacles, a muscular foot and a visceral mass housing the organs.
So they don't necessarily have external shells. Some have internal shells, like squids, or no shells (octopusses).
Now you know.
By min | October 27, 2006, 10:57 AM | Science
What's with the mollusk info? Not that it's not appreciated, but is there a specific reason for it to be brought up? Is it for the comic you're doing with Himmler?
I like bacon.
learn something new everyday!