Date of this Version
Since the publication of "The Arrhenuri of the United States," in 198, the author has been fortunate enough to secure enough more material to justify the publication of a supplementary paper on this large genus of water-mites. This material consists of collections from new localities in the United States, and of additional material from old collecting grounds, together with a few specimens from other countries. The author's own collections were made in Wisconsin and Illinois. A few new places were visited, as the lakes about Milwaukee ; and more extensive collections were made in previously known bodies of water, as Lake Wingra, Mirror Lake, Lake Spooner, Wisconsin, and the Illinois River at Havana. As a result, several hundred more Arrhenuri have been studied, representing twenty-eight species; the habitats of eleven species have been extended beyond state lines, and three new species have been added to the genus, while four more females have been identified.