COCCONEIS GERMAINII SP. NOV. AND A RELATED TAXON FROM KERGUELEN ARCHIPELAGO (AUSTRAL OCEAN, INDIAN SECTOR)

Abstract

This paper presents light (LM) and scanning electron microscopic (SEM) observations on two small Cocconeis taxa from Kerguelen Archipelago (Indian Sector of the Southern Ocean). The new species Cocconeis germainii sp. nov. is described. Previous works show that this species, or morphologically similar varieties with lower striae density, have already been illustrated and briefly described under various names. Most of these descriptions are based either on incomplete frustules or probably juxtaposed sternum and raphe valves. Several other taxa showing a certain degree of morphological affinity with the sternum valve of C. germainii are discussed. Included in this group are Catillus subimpletus Hendey and a so-far unidentified Cocconeis sp. [aff. C. peltoides Hustedt]. The generic status of Catillus, established by N.I. Hendey, is briefly discussed.