The sexspiaosa-group of the ant genus Polyrhachis F. Smith (Hym. Formicidae)

The sexspinosa-group of Polyrhachis is revised. Twelve species are recognised, two of which are described as new. Sixteen synonyms are recognised, mostly of infra-specific taxa. A key to the species and diagnostic notes of each species are included.     

Protozoa in Planktonic Food Webs1,2

Protozoa are now being recognized as important members of planktonic food webs. This is due to the inclusion of microbial links in our paradigm of trophic relationships. Heterotrophic microflagellates and ciliates are major grazers of bacteria. They can stimulate production through nutrient recycling and can transform microbial production into larger particles, which are then available for macroconsumers. In this paper we add new groups, the small (< 20 μm) ciliates and myxotrophic flagellates, to the planktonic food web.