The collection of material for the preparation of this list, was begun in June, 1897, and was finally suspended about April 1, 1898. During the summer vacation, numerous collections were made from all places in the vicinity of Greeley, Colorado, which appeared to be favorable “fishing-grounds” for Protozoa. From the beginning of the present school year to the first of April, 1898, collections were made at less frequent intervals. Infusions of various substances were kept in the laboratory and examined from time to time. The classification adopted is that of Doctor O. Bütschliin "Bronn’s Klassen und Ordnungen des Thier-Reichs”, upon which I have relied for nearly all my determinations as far as genera. Other works, which nave been of great value in the determination of species, are Pénard’s “Études Sur les Rhizopodes D’Eau Douce”, kindly loaned me by Prof. Gardiner; Leidy’s “Fresh-Water Rhizopods of North America", and Pritchard’s “History of Infusoria”.
Beardsley, Arthur Eugene, "A List of Protozoa Observed at Greeley, Colorado: With Notes Upon Their Habits and Modes of Reproduction" (1898). University Libraries Digitized Theses 189x-20xx. 4.