46 1 Proceedings of the Oliio Stale Academy of Science. 



In preparing tlie keys, the most apparent characters possible 

 have been employed. The aim has been to produce accurate and 

 usable keys, rather than to exhibit relationships of species. Some 

 of the keys have been tested by use by mycology students at 

 Miami University for several 3^ears and at the Ohio State Uni- 

 versity during the present year. Most of them have been re- 

 vised several times as suggested b_v use. 



The work is based largely on published descriptions, and 

 in some cases altogether. These are sometimes so brief or so 

 lacking in precise detail that it has been difficult to find reliable 

 and well-marked characters upon which to separate species. 

 This is especially true of species founded wholly upon dried 

 specimens. 



Notwithstanding such errors, misconceptions and incorrect 

 conclusions as doiibtless occur, it is believed that the paper will 

 prove helpful to students, amateur mycologists and others in 

 the determination of Ohio Agarics. It is ofi^ered as a summary 

 of our present knowledge of the Ohio plants, and is to be re- 

 garded as only a preliminary study. 



It is not within the. scope of this paper to discuss the species 

 in detail, so that many points of interest and of some impor- 

 tance must necessarily be omitted. With each species included, 

 however, a list of references to the most available and useful 

 works is given. One or more of these should always be con- 

 sulted before reaching a decision as to the determination of 

 any plant. 



The matter of the classification and nomenclature of the 

 Agaricaceae is still in an unsettled condition. It has seemed best 

 in most instances to follow the arrangement given by Saccardo 

 in his Sylloge Fungorum for two reasons : It is not the piu'- 

 pose to present a critical study of the nomenclature of the family, 

 and most of the available works on this group will be found to 

 follow a similar system. 



The writer wishes here to acknowledge his many obligations 

 to Dr. P)ruce Fink tmder whose direction the work was under- 

 taken. He is also indebted to Dr. W. A. Murrill for the privilege 

 of examining specimens in the herbarium of the New York 



