;i Prodromus of an American Cryptogamous Flora can be attempted, 

 it will therefore be nercessary to ascertain from the different regions 

 of our continent, what are the treasures it contains — and the Author 

 most earnestly and respectfully requests to be favoured with informa- 

 tion and specimens from every quarter, in order to effect that object. 

 A considerable collection of European specimens, determined by the 

 hest German Cryptogamists, an adequate collection of Books on most 

 of tin 1 (lasses, and a pretty intimate acquaintance, especially with 

 the Fungi of Europe, together with excellent instruments, have 

 greatly assisted him in the exertions he has hitherto made — and he 

 flatters himself, that those botanical friends, who have applied to him 

 for communication of specimens, have been in some degree satisfied, 

 by what he has been enabled to send them. The present work is 

 destined to call the attention of Botanists to the subject; and if this 

 should be effected, the Author will, with pleasure, from a conciousness 

 of its unavoidable imperfections, consign it to oblivion. He has, 

 however, been fortunate enough, to obtain specimens of almost every 

 single hepatic moss hitherto noticed as indigenous to America, and to 

 augment the number considerahly, so that he entertains a hope, that 

 the present sheet may prove useful, as far as it goes, in the determi- 

 nation of this class of Cryptogamous vegetables. 



It only remains for him to state, that the Musci Hepatici are ar- 

 ranged according to Dr. F. Weber s Historia Muscorum Hepaticorum, 

 Kiel 1815 ; that he has carefully compared them with European spe- 

 cimens, of which his collection contains the greater part ; and that 

 he has not ventured to establish a new species, unless absolutely con- 

 vinced of its specific difference. The explanation of the signs and 

 abbreviations made use of, will enable the Botanist to judge, what 

 degree of confidence is due to the Author's determinations. 



Besides the Work of Dr. Weber just cited, reference has been had 

 throughout to Dr. Schwagcrichcn's Prodrom. Hist. Muse. Hepatic ; 

 to Michaux Flora Am. Borealis ; to Dr. Muhlenberg's Catalogue: 

 to the Catalogue of New-York Plants, published by Dr. Torry ; and, 

 in some instances, to Dr. Roth's Flora Germanica. the descriptions 

 of the latter being particularly ample. Unfortunately, the Author 

 has not been able to procure Hooker's Monography of the Jungerma- 

 nias ; nor English Botany of Sowerby : so that he was under the 

 necessity of contenting himself with Weber's citations from these. 



Ardently hoping that his attempt will be acceptable to American 

 Botanists, notwithstanding its manifest imperfections; and that it 

 may prove the means of doing them away in a future more compre- 

 hensive work, by eliciting the necessary corrections and information. 

 the Author respectfully subscribes himself, 



LEWIS D. DE SCHWEINITZ. 



Salem, Stokes County, North -Carolina. 



