A population of Amphora micrometra Giffen, collected in September 2002 from different habitats in Laguna Blanca in the Bolivian
Altiplano, South America, has been examined using light transmission and scanning electron microscopy. The original description of this
species is incomplete and insufficient to characterize the taxon in the light of the newly collected ultrastructural data. The holotype of
A. micrometra was examined during the present study and compared to Bolivian specimens. An emended diagnosis of A. micrometra using
all available information is provided. A taxonomic discussion based on available literature and the ecology of the taxon is also presented
herein.