A Revision of the Comatulid Genus Stephanometra AH Clark With a Rediagnosis of the Genus Lamprometra AH Clark (Echinodermata: Crinoidea)

Several genera in the comatulid crinoid family Mariametridae are currently ambiguously distinguished on the basis of variations in length and robustness of oral pinnules. Previous descriptions have suggested that at least the genera Stephanometra and Lamprometra , both common and widespread on Indo-western Pacific reefs, are imperfectly distinguishable. A detailed morphological re-examination supports distinct Stephanometra and Lamprometra . The five currently recognized species of Stephanometra are reduced to two: S. echinus under S. tenuipinna , and S. spicata (inlcuding S. oxyacantha ) and S. spinipinna under S. indica . Of specimens examined in the indica-spicata-oxyacantha series, 20% are intermediates that cannot be satisfactorily assigned to species based on current diagnoses. In Lamprometra , L. klunzingeri and L. palmata gyges are formally reduced to infrasubspecific variants of L. palmata .