75 



After one and one half years of work, including manj- thorough 

 examinations of the Lichen Herbarium of the New York Botan- 

 ical Museum ; 30 days spent in the field and much time consumed 

 in the identification of species, a list has been prepared comprising 

 over 300 species taken from an area included within the limits of 

 a circle, the center of which is City Hall, New York City, and the 

 radius of which is 100 miles. 



This list is by no means complete. Yet I consider it to be a 



beginning large enough to justify me in presenting it at this 



time. It is hoped that many new species, hitherto unknown in 



this locality, together with many new habitats may subsequently 



be added. 



Boundaries 



A circle drawn with its center at City Hall, New York C'lW, 

 and having for its radius a line 100 miles in length, will include 

 the greater part of Long Island; the whole of Staten Island; the 

 greater part of New Jersey; parts of Pennsylvania; New York 

 state as far north as Catskill and more than half of Connecticut. 



It has been the custom of the Torrey Botanical Club to include 

 within the 100 mile radius all of Connecticut, all of New Jersey, 

 all of those counties of Pennsylvania which are touched or crossed 

 by the circle, all of Long Island, while the northern boundaries 

 of Green, Delaware, and Columbia counties are taken as the 

 most northern boundaries of the area situated within the borders 

 of New York state. 



This list, however, will include no lichens other than those 

 which have been identified as existing strictly within the 100 

 mile radius. 



Ecology 



The territory included within the above boundaries is espe- 

 cially well adapted for lichen study. It is perhaps as rich in this 

 flora as any other area of similar size in the U^nited States. 

 District No. i, including Staten Island, is perhaps most scanty 

 in the lichen flora, while the Hudson region, including District 5, 

 is very rich in all forms. 



Two leading facts concerning the habitats of lichens make it 

 comparatively easy to determine why they are found in abun- 



