PRELIMINARY ENUMERATION 
OF THE 
Lichens of Lancaster County, 
PENNSYLVANIA. 
By a. ARTHUR HELLER. 
In “ Mombert’s Authentic History of Lancaster County,” pub- 
lished in 1869, Dr. Thos. C. Porter enumerated 1 169 species of 
flowering plants, 47 species of ferns, 125 species of mosses, and 
27 species of liverworts. Since that time almost one hundred 
species of flowering plants and a number of mosses have been 
added. But little attention has been paid to lichens thus far, and 
only a few collected. 
The present list in which seventy-eight species and varieties 
are enumerated, is a crude endeavor to give this interesting 
branch of botany the impulse and recognition which it deserves 
in this county, so rich in plant life. 
With the exception of a few collected by Mr. Small and my- 
self in 1890, and several contributed by Dr. Porter, all the species 
enumerated were collected by myself during November, 1892. 
There can be no doubt that further and more thorough explora- 
tion will double or triple the number. 
I have noted in nearly all cases the situations in which the 
plants were found, as it is an interesting matter to observe to 
what extent an individual species is restricted in habitat, or how 
widely it may be distributed. 
I am indebted to Dr. N. L. Britton, who kindly gave me the 
opportunity of comparing my specimens with those in the her- 
barium of Columbia College, and to Dr. John W. Eckfeldt for 
revising and correcting my determinations. 
Lancaster, Pa., February 15, 1893. 
