External morphology of the choanoflagellateSalpingoeca gracilisJames-Clark

Abstract

In his search for evidence illustrating the botanical/zoological affinities of the sponges (Porifera), James-Clark (1867) studied a number of colourless flagellates. The genusSalpingoeca(Craspedophyceae, Christensen, 1962; cf. Chadefaud, 1960) was thus erected to comprise certain solitary, lorica-dwelling organisms, characterized by a single anterior flagellum encircled by a ‘filmy, membranous, colourless collar’ (James-Clark, 1867).About fifty species (approximately twenty marine) are at present allocated to this genus, provided it is defined as e.g. by Norris (1965) and Bourrelly (1968) (i.e. includingLagenoecaKent andPachysoecaEllis).