African Invertebrates » Архив номеров » Vol. 52, Issue 1 » Публикация

Аннотация This paper focuses on five species of Polyplacophora (Mollusca) collected from Lavanono, southern Madagascar. Ischnochiton sirenkoi is described as a new species and is compared with the two Ischnochiton species known from Madagascar, I. yerburyi (E.A. Smith, 1891) and I. sansibarensis Thiele, 1909, and with all known Indian Ocean Ischnochiton species. Findings for the other species here discussed provide a significant extension of previously known geographical range. Chaetopleura chelazziana Ferreira, 1983 is reported for the first time in the chiton fauna of Madagascar. The taxonomic status of Callistochiton ashbyi (Barnard, 1963), previously considered a synonym of C. crosslandi Sykes, 1907, is discussed. This taxon, which was described from a unique intermediate valve from South Africa, is re-evaluated and recognized as a valid species, differing from C. crosslandi in several significant characters. We also present an unusual feature detected in almost all the specimens of Cryptoplax dupuisi Ashby, 1931, which are characterized by the absence of dorsal girdle spicules on the first four valves, a feature never reported in other chiton species. Type material of Callistochiton madagassicus Thiele, 1909, Chiton ashbyi (Barnard, 1963) is figured.