Some members of the diverse genus "Beroe" may occasionally attain a length of up to , though most species and individuals are less than about 10 cm; "Neis cordigera" is among the largest species in the class, often exceeding in length. The body is melon or cone-shaped with a wide mouth and pharynx and a capacious gastrovascular cavity. Many meridional canals branch off this and form a network of diverticulae in the mesogloea. There are no tentacles but there are a row of branched papillae, forming a figure of eight around the aboral tip.