Tins work was originally intended to embrace, as far 

 as practicable, only those species of Mossee peculiai to 

 that portion of North America lying east of the Missis- 

 sippi River and south of the greal lakes and the river 

 St. Lawrence, and of which satisfactory figures had not 

 been published. 



Considerable progress had been made in the drawings 

 and engraving, when it was ascertained that not a few 

 species, previously regarded as natives only of Eastern 

 North America, occurred also in Japan and on the adja- 

 cent coast of China.* These species, notwithstanding, 

 have still been here retained, together with two or 

 three others from California, for the reason that either 

 no figures of them, or insufficient ones, have heretofore 

 been given. 



On the other hand, it will be seen that several spe- 

 cies, strictly confined within the proposed limits, are 

 omitted : this is owing to the fact that of some of them 

 excellent figures have elsewhere appeared ; and of oth- 

 ers, that specimens suitable for illustration were not at 

 command. 



* See " Characters of New Mosses, collected by Charles Wright in the North 

 Pacific Exploring Expedition under the Command of Captain John Rodger*, by 

 Wm. S. Sullivant and Leo Lesquereux," in the Proceedings of the American 

 Academy of Arts and Sciences, Vol. IV. p. 2 75, 1859. 



2S814 



