Nereis
Nereis is a genus of polychaete worms in the family Nereidae. It comprises many species, most of which are marine. The mouth of the nereis is located on the peristomium, the segment behind the prostomium, and varies in form depending on their diet, since the group includes predators, herbivores, filter feeders, scavengers, and parasites.
In general, however, it possesses a pair of jaws and a pharynx that can be rapidly everted, allowing the worm to grab food and pull it into the mouth. In some species, the pharynx is modified into a lengthy proboscis. The digestive tract is a simple tube, usually with a stomach part way along, which eventually leads to a rectum and anus where fecal matter is excreted.
In general, however, it possesses a pair of jaws and a pharynx that can be rapidly everted, allowing the worm to grab food and pull it into the mouth. In some species, the pharynx is modified into a lengthy proboscis. The digestive tract is a simple tube, usually with a stomach part way along, which eventually leads to a rectum and anus where fecal matter is excreted.