Ill 



PREFACE* 



The aim in the preparation of this Manual has been to 

 make it a practical handbook applying particularly to the 

 region of Western Pennsylvania and embodying all that is at 

 present known regarding the occurrence and distribution of 

 mosses within that area. As a matter of fact, the Manual will 

 be found to apply also to the adjacent regions of central Penn- 

 sylvania, extreme southwestern New York, eastern Ohio^ and 

 northern West Virginia. 



When the present writer took charge of the botanical col- 

 lections in the Carnegie Museum in 1904 he found that the 

 Herbarium, aside from certain specimens collected by Mr. D. 

 A. Burnett in M.cKean County, a few years previously, con- 

 tained but little to represent the rich flora of mosses and liver- 

 worts to be expected in the western end of Pennsylvania. One 

 of the aims at the Herbarium of the Carnegie Museum has 

 been to assemble a very complete and comprehensive collec- 

 tion of all the plants to be found in the general region in which 

 Pittsburgh is situated, and, in the prosecution of this work, 

 the writer has been enabled to visit all of the counties in the 

 western half of Pennsylvania and also adjacent portions of 

 Ohio and West Virginia. Certain localities in this general re- 

 gion have been made the subject of detailed ecologic and sys- 

 tematic study and collection — particularly the peninsula of 

 Presque Isle, near Erie, Pennsylvania ; the extensive Pymatun- 

 ing Swamp in Crawford County, Pennsylvania ; the mountain- 

 ous region in the vicinity of Ohio Pyle, Fayette County; and 

 the larger portion of Allegheny County, especially in the 

 vicinity of Pittsburgh. From these and other localities visited 

 extensive collections of mosses have been made and the amount 

 and representative nature of the herbarium material thus avail- 

 able for study have become such that it has been deemed ad- 

 visable to prepare a treatise embodying the results of the work 

 accomplished, thus placing within the reach of other students 

 of the mosses within the region a convenient means of identify- 

 ing and checking up their own collections. It is hoped that 

 with all its faults this Manual may be to some extent the 

 means of stimulating bryological study in a region of whose 

 mosses there is yet much to be learned. 



In the preparation of this Manual the author has taken 

 as the taxonomic standard the monumental work of Warn- 

 storf, Ruhland, and Brotherus, brought to completion in 1909, 

 in Engler & Prantl's "Die Natuerliche Pflanzenfamilien," Teil 

 I, Abteilung III. In the characterization of the various orders, 



* This work in a more condensed form was submitted as a major thesis in 

 candidacy for the degree of Doctor of Philosophy in the tJniversity of Pittsburgh, 

 June, 1911. 



