The following pages are designed to contain brief de- 

 scriptions of all the Musci and Hepatic^ hitherto detected 

 in that portion of the United States lying east of the 

 Mississippi E-iver. A few species found elsewhere, either 

 new, or having a geographical range heretofore unnoticed, 

 or for some other special reason, have also been described ; 

 namely, those from Texas and New Mexico, and also 

 several from near our northern boundary, and likely to 

 occur within it. 



The territory within the limits adopted — extending, as 

 it does, from 25'^ to 47° North Latitude, and traversed for 

 nearly its entire length by mountain ranges, reaching, at 

 several points in their northern and southern terminations, 

 an alpine elevation — presents conditions favorable to a 

 copious and varied muscological vegetation. And if the 

 number of species here recorded is not so large as that 

 found in an equal area similarly situated on the Eastern 

 Continent, it must be borne in mind that our Bryology 

 and Hepaticology (particularly the latter) have thus far 

 been very imperfectly investigated. Scarcely any portion 

 of our country, excepting Central Ohio, has been carefully 

 examined. The mountain ranges have only been cursorily 

 visited by a few interested in these branches of Botany. 

 In the northern section, notwithstanding numerous dis- 

 coveries made by the late Mr. Oakes, and the more re- 

 cent ones (among them a Dicheli/7na, a Tetrodontiuin, and 



