Discriminant analysis of Indo-West Pacific Flabellum

CAIRNS, S.D., 1989:10:30. Discriminant analysis of Indo-West Pacific Flabellum. Mem. Ass. Australas. Palaeontols 8, 61-68. ISSN 0810-8889. Stepwise discriminant analysis was performed on 145 specimens of Indo-West Pacific Flabellum pertaining to 8 putative species. Posterior classification supported the premise of 8 species at the 99.3% level. Only two characters are needed to distinguish all species at the 0.01 level: lesser calicular diameter and crest height. Among the first 3 canonical variables, which explain most (95.7"7o) of the variation, 6 characters proved to be most highly weighted: edge angle, crest height, lateral edge length, lesser calicular diameter, greater calicular diameter, and height. Subsequent inclusion of type specimens into the classification revealed that the 5 syntypes of F. patens are all different species; the 5 syntypes of F. pavoninum represent 2 species, one of which is F. dislinclum; F. magnificum, F. lamellulosum, and F. vaughani are all distinct species; the east African species is poorly known and difficult to distinguish; and 2 unnamed species remain. Discriminant analysis is highly recommended as a statistical procedure to distinguish species that have few qualitative differences, and to subsequently identify specimens, or assign types, following a preliminary analysis that does not include the type specimens. Stephen D. Cairns, Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution. Washington, D.C. 20560, U.S.A.; received27 July 1988.