Claparède, 1870
Worms with flattened body. Prostomium broad with four antennae, no palps and poorly developed eyes. Eversible proboscis, simple and unarmed. With three tentacular cirri on the first one or two segments which may lack setae. Parapodia uniramous with dorsal and ventral cirri. Setae mainly compound with serrated end-pieces. The serrations are of taxonomic importance and must be examined in lateral view (Pleijel and Dales, 1991). Pygidium without cirri.
Practically nothing is known of the biology of this group. None have ever been found with food in the gut, but certainly they do not feed on phytoplankton (Day, 1967). Uschakov (1972) speculated that the simple hook-shaped setae of the first modified parapodia of Lopadorhynchus might hold the prey.
Four genera:
Genus Lopadorhynchus Grube, 1855
Lopadorhynchus appendiculatus
Lopadorhynchus brevis
Lopadorhynchus henseni
Lopadorhynchus krohni
Lopadorhynchus nationalis
Lopadorhynchus uncinatus
Genus Maupasia Viguier, 1886
Maupasia coeca
Maupasia gracilis
Maupasia isochaeta
Genus Pedinosoma Reibisch, 1895
Pedinosoma curtum
Genus Pelagobia Greeff, 1879
Pelagobia longicirrata