Diodora

Abstract: A new genus, Scelidotoma, type species Emarginula bella Gabb, is proposed for three North Pacific species, and a new name, Diodora arnoldi, is proposed, with adequate description, for "Diodora murina" of authors, not of Arnold, 1903. During the course of a revision of the Fissurellidae of the temperate provinces of western North America, I have found that one new genus is needed and also a new name for a species. Preliminary to the use of these names in a dissertation submitted to Stanford University I am here describing them.

Abstract: The mollusc Diodora ruppellii (G. B. Sowerby I, 1835) (Gastropoda: Lepetellida: Fissurellidae) is reported here for the first time as an alien species in Libyan coastal waters. Field surveys conducted throughout the winter period of 2018–2019 along the sandy shoreline bordering Tripoli Harbour yielded fourteen empty shells and one live specimen, all found within accumulating shell middens. While the finding of D. ruppellii in close proximity to Tripoli Harbour may allude to its introduction via shipping traffic, natural dispersal from nearby, known or yet undiscovered, Mediterranean populations cannot be ruled out. The current study forms part of a larger ongoing programme investigating the marine fauna of the littoral zone with a focus on the identification of non-native species. As D. ruppellii is so far recorded from Libya as based on the present punctiform record, we rank it here as a casual (i.e. not established) species in the country.