IOWA ACADEMY OF SCIENCES. 
19 
mentions this same American lichen and no more. How- 
ever, it must be stated also that Petiver had, in the second 
century of his mosses in 1695 (Petervarini Musci Cent.) 
sent out Parmelia perforata, under the descriptive designa- 
tion, Lichen arboreus Americanus scutellis magnis donatus; 
but I am unable to ascertain whether from North or South 
America. Also, H. Sloane in his “Catalogus Plantarum 
Jamaicae,” London, 1696, is said to have mentioned seven 
species of previously known lichens under some sort of 
classification. This work I have not yet investigated 
sufficiently to be certain but that we should carry our his- 
tory back to 1696 at least. But turning to tangible things, 
our Sticta damaecornis is the eighty-sixth known lichen 
recorded by Kremplehuber, and the title under which the 
plant appears is the forty-first of his references to lichen 
literature. Next in order, it is certain that Gronovius 
in his “Flora Virginica,” 1789-1743, listed nine North 
American species with short diagnoses. Among these were 
Evernia lacunosa , Parmelia perforata and seven other very 
common and conspicuous species. After an interval of 
four decades, we hear of the study of American lichens 
again through the work of 0. Swartz in the West Indies, 
1788-1808. In three editions of his work, he gives lists, 
descriptions and illustrations of 25 lichens. These are 
common plants, all recorded in Krempelhuber’s “Ges- 
chichte,” and these pages need not be burdened with the 
names, though it may be in order to state that all but the 
last three were placed under the genus, Lichen. During 
these years, H. Muhlenberg, in his “Index Flora Lan- 
castriensis,” 1793, gives a list of 27 species with no 
authorities and all under the genus, Lichen . Also in 1803, 
Michaux, in his “Flora Boreli- Americana,” noticed 21 
species of North America, of which 7 new ones may be 
found listed in Krempelhuber’s “Geschichte.” Likewise, 
in 1803 appeared Acharius’ “Methodus,” in which are 
mentioned with descriptions a considerable number of 
North American lichens, but usually without any state- 
ment as to distribution, so that it is impossible to know 
just which ones the author knew from America. 
