Idanthyrsus Kinberg, 1867

Type species. Idanthyrsus armatus Kinberg, 1867, by monotypy.

Diagnosis (modified after Capa et al. 2012). Operculum completely divided into two lobes. Two rows of opercular paleae. Outer paleae straight with sharp lateral denticles. Inner paleae straight, cylindrical. One or two pairs of nuchal hooks with or without limbation on the concave margin. Multiple compound tentacular filaments. Median ridge with lateral eyespots. Median organ small without eyespots. Three parathoracic segments.