Genus Aspidosiphon Diesing

Remarks. Cutler and Cutler (1989) recognised two subgenera, Aspidosiphon (Aspidosiphon) Diesing, and Aspidosiphon (Paraspidosiphon) Stephen, and erected a new subgenus, Aspidosiphon (Akrikos) . The fisrt two subgenera can be separated on the basis of the form of the longitudinal muscle layer (continuous vs separated bundles). Aspidosiphon (Akrikos) differs from the other two genera by the absence of hooks, or if present, the hooks are not arranged in rings. Two species, Aspidosiphon (Aspidosiphon) muelleri Diesing, and Aspidosiphon (Paraspidosiphon) coyi de Quatrefages, are reported in the present study.