The Hirudinea of Illinois

This paper is a partial descriptive catalogue of the leech fauna of Illinois. It is founded on collections gathered from time to time during the past twenty-five years hy the Illinois State Laboratory under the direction of Prof. S. A. Forbes, of which material by far the most important part, as regards both number of species and individuals and state of preservation, is that taken by Prof. Frank Smith and other members of the staff of the Illinois Biological Station. For the opportunity of studying this material I am indebted to the interest and courtesy of Professors Forbes and Smith. No doubt other species occur in this region ; indeed several others have already been recorded from the State.Ope