Transform Boundaries The final type of boundary is one where the two plates slide against each other in a sideways motion. These boundaries between plates is referred to as transform boundaries.
The three regions of the body of the Mollusk are the head-foot, the visceral mass, and the mantle-shell.
Mollusks. Resources. Mollusks (phylum Mollusca) are the second largest group of invertebrates (arthropods are the largest), with over 100,000 species. They are characterized by a head with sense organs and mouth, a muscular foot, a hump containing the digestive and reproductive organs, and a covering of tissue (the mantle) that usually secretes a hard, protective shell.