Abstract
Surirella engleri, including its four original infraspecific taxa, was studied and typified using historical East African material from which Otto Muller described more than 100 new diatom taxa at the beginning of the 20th century. Considerable outline variation was found, in agreement with the results of experimental cultures carried out in the late 1980's on material from the northern basin of Lake Tanganyika. This variation supported the abandonment of taxonomie recognition of the four infraspecific taxa proposed by Müller. SEM analyses of this taxon from the original Lake Malombe material and from the recent Lake Tanganyika material showed some minor differences. The past and current distribution of this taxon which is endemic to Tropical Africa was summarized.