Revision of Genera and Species Composition of Lower Centroheliozoa. II. Family Raphidiophryidae n. tam.

Abstract

A revision of the genus Raphidiophrys ARCHER on the basis of the scale structure is performed. Two new genera are proposed. Parasphaerastrum gen. nov. includes a single species, P. marina (OSTENFELD) emend. MIKRJUKOV, surrounded by the envelope of rod-like tangential siliceous spicules. Polyplacocystis gen. nov. includes five species, two with reticulate [P. ambigua (PENARD) and P. symmetrica (PENARD)] and three with smooth [P. pallida (SCHULZE), P. marginata (SIEMENSMA) and P. pedunculata (MIKRJUKOV)] surface of scales. Six other EM-studied species [R. capitata SIEMENSMA et ROIJACKERS, R. elegans HERTWIG et LESSER, R. intermedia PENARD, R. minuta NICHOLLS, R. Viridis ARCHER and R. ovalis (Dü;RRSCHMIDT)], which have complex scales formed by two parallel plates and internal septae between them, are retained in the genus Raphidiophrys ARCHER. Only three species with plate-scales identical to those in Polyplacocystis (R. lemani PENARD, R. tubifera PENARD, and R. glabra NICHOLLS et 0üRRSCHMIDT) stay in the genus Raphidocystis with the emended diagnosis given by NICHOLLS & DüRRSCHMIDT (1985). The new family Raphidiophryidae is proposed including the genera Parasphaerastrum, Polyplacocystis, Raphidiophrys and Raphidocystis. A key for the species of these genera is proposed.