BLASTOCRITHIDIA N.G. (MASTIGOPHORA: PROTOMONADINA) FOR CRITHIDIA (IN PART), WITH A SUBARCTIC RECORD FOR B. GERRIDIS (PATTON)

Abstract

Two quite distinct genera of the family Trypanosomidae Doflein have been confused under the name of Crithidia Léger, which, as shown by Wallace some years ago, is properly referable only to certain small, truncate insect flagellates having a stiff flagellum emerging from a funnelled anterior depression, and never at any stage possessing an undulating membrane. However, an error of 50 years' standing still results in the allocation to this genus of arthropod parasites characterized by a paranuclear kinetoplast from which a flexile flagellum proceeds anteriorly along the outer edge of an undulating membrane. It is now proposed that such flagellates be referred to Blastocrithidia n.g. The selected genotype, B. gerridis (Patton, 1908), a parasite of water striders (Hemiptera: Gerroidea), is recorded from northern Canada for the first time.