Results of the Rumphius Biohistorical Expedition to Ambon (1990). Part 17. The Cephalaspidea, Anaspidea, Pleurobranchida, and Sacoglossa (Mollusca: Gastropoda: Heterobranchia)

This is the final report describing the heterobranch molluscs collected by the Rumphius Biohistorical Expedition to Ambon during November and December 1990. This part deals with the non-nudibranch higher clades (Cephalaspidea, Anaspidea, Sacoglossa, and Pleurobranchida). Forty-one species belonging to 21 genera are identified from Ambon and nearby localities in the central Indonesian archipelago; 2 species are new to science, and 3 species are new records for Indonesia. The new species Haminoea edmundsi is described from the mangroves near Paso in Ambon Bay, and the new species Mourgona anisti is described from Latuhalat, also Ambon. A discussion and table of all named species of Plakobranchus are provided, and the original descriptions and museum specimens from other localities are compared in an effort to clarify some of the problems surrounding these species. Chelidonura sandrana Rudman, 1973 and C. babai Gosliner, 1988 are synonymised with C. tsurugensis Baba & Abe, 1959. Recent corrections of names and/or dates of publication are highlighted: Phanerophthalmus olivaceus (Ehrenberg, 1828), Aplysia argus Ruppell & Leuckart, 1830, Dolabella auricularia ([Lightfoot], 1786), Elysia faustula Bergh, 1871, Cyerce elegans Bergh, 1870, Euselenops luniceps (Cuvier, 1816), and Pleurobranchus peronii Cuvier, 1804.