The parts of the digestive system that one would see in a cross-section, anterior to the gizzard of an earthworm includes; thecrop, esophagus, pharynx, mouth cavity. The digestive system of an earth worm is divided into many regions all with a specified function. It consists of the pharynx, the esophagus, the crop, the intestine and the gizzard.
Mollusks is the group of invertebrates that made up the majority of the Marine species. Their bodies tend to not divided into segments like other organisms.