Fischer, 1883
This family differs most conspicuously from the Atlantidae by the size and shape of the body. The body is basically cylindrical and is greatly enlarged and elongated, covered by a cutis of varied thickness. The body is divided into three regions; proboscis, trunk and tail. The proboscis is more or less distinct from the head region, located at the anterior end of the trunk. A stalked visceral nucleus is located at the posterior end of the trunk, and is followed by a tail. Although a shell is present, it is reduced to either a cap-like structure over the visceral nucleus or a microscopic remnant of the larval shell, located dorsally on the visceral nucleus. A fin sucker is present in both sexes, but is much smaller than in the Atlantidae. The location of the sucker on the posteroventral margin of the foot and its remoteness from the mouth make its use in feeding improbable. It may be used during mating to hold the male and female together, however such behavior has not been observed. The radula in all Carinariidae is broadly triangular and has a relatively low and limited number (34 to 44) of tooth rows (type II radula). The central tooth has a broad, low base with well-developed posterio-lateral processes and three long cusps (He 4c). The lateral teeth have a smaller, curved cusp on their inner accessory plate (in addition to the main cusp). This cusp is more conspicuous in the genus Carinaria than in the other two genera. The marginal teeth are monocuspid (He 4a). According to Tesch (1949) the radulae show few differences among the different genera and species of Carinariidae, whereas Vayssière (1904) and Bonnevie (1920) obviously overvalued its taxonomic value in the family. (For morphogenesis of radular teeth in the Carinariidae see Richter, 1968).
Genus Carinaria
Carinaria lamarcki
Carinaria challengeri
Carinaria cithara
Carinaria cristata
Carinaria japonica
Genus Cardiapoda
Cardiapoda placenta
Cardiapoda richardi
Genus Pterosoma
Pterosoma planum