Almidae

The animal family Almidae includes about six genera of segmented worms.

A notable peculiarity of some species in this family is a tendency to extensions of the body wall in the vicinity of or including the male pores. These extensions may be mere protuberances, as in some species of Drilocrius; or involve a greater extent of the body wall, as in genus Glyphidrilocrius. They take the form of wing or keel-like structures called alae in Glyphidrilus species and paddle-shaped claspers in Drilocrius alfari.