This study analyses diatom diversity and relative abundance in Pulmari lake
(39 degrees 07' S; 71 degrees 05' W), in the Patagonian Andes Neuquen, Arg
entina). 147 diatom taxa were identified, 24 infrageneric taxa are new reco
rds for Argentina and a new variety Navicula willeri KRASSKE var. triundula
ta is described.