THE GENUS ATTHEYA. I. A DESCRIPTION OF FOUR NEW TAXA, AND THE TRANSFER OF GONIOCEROS SEPTENTRIONALIS AND G. ARMATAS

Abstract

Four new taxa belonging to the genus Attheya West are described from the west coast of Britain and from the North Sea. Attheya arenicola sp. nov. was found on sandy beaches in southwest Wales, Cornwall and the west coast of Scotland in the U.K., and on the edge of the North Sea at Renesse, Netherlands. A. flexuosa var. flexuosa sp. nov. and A. flexuosa var. enodulifer sp. nov. have been found in a similar habitat attached to cells of Hantzschia Grunow and Bacillaria Gmelin spp. A. longicorrus sp. nov. attaches to other diatoms in the plankton. Using light and electron microscopy, they are compared with A. decora West, the type species of Attheya, and with Chaetoceros sessilis Grøntved, Gonioceros armatus (T. West) H. & M. Peragallo and Gonioceros septentrionalis (Østrup) Round, Crawford & Mann. It is suggested that all taxa should be placed within Attheya because of similarity of horn structure and habitat preferences.