On the Lichens near New-York. 5 



iinguishable by its light lake or rose-coloured crust, which is 

 very thin and rough. The apothecia are oval, minute, scat- 

 tered, and of a deeper colour than the crust. 



2. Arthonia. 



1. punctiformis. JIch.p.4. On smooth bark. Crust white ; 



apothecia small, subimmersed. 



2. Swartziana. Id. p. 5. On old trunks of trees. Crust 



white ; apothecia broad and confluent. 



3. astroidea. Id. p. 6. On smooth bark. Crust ashy and 



glaucous ; apothecia flat, stellate, and shapeless. 



4. obscura. Id. p. 6. Ibid. Crust olivaceous; apothecia 



small, oval, uniform, subimmersed. 



ff Apothecia with a raised margin. 



3. Lecidea. 



Frond crustaceous, uniform. 



* Apothecia constantly black. 



i. atro alba. Id. p. 11. Common on rocks. Areola? of the 



crust black and white. 



2. fumosa. Id. p. 12. Ibid. Crust dull smoky colour ; apo- 



thecia sunk into the crust, grayish within. 



3. pantosticta. Id. p. 13. Ibid. Apothecia minute ; im- 



mersed in the crust upon the areola?. 



4. lapicida. Id. p. 13. Ibid. Apothecia mostly between 



the areola?. 



5. petrma. Id. p. 15. Ibid. Distinguishable by the con- 



centric tendency of the apothecia. 



6. conflluens. Id. p. 16. Ibid. To the naked eye like No. 1 



and 4; crust dirty white; apothecia irregular and ag- 

 gregated. 



7. premnea. Id. p. 17. Trees and fences. Apothecia with 



a whitish stratum under the disk. 



8. parasema. Id. p. 17. Bark. Crust generally bordered 



by a black line ; apothecia blackish within. 

 0. enteroUuca. Id. p. 19. Trunks. Apothecia internally 

 white. 



