88 "UMBILICARIA. 



plicate, and becoming lirellose, and immarginate. Spores ellip- 

 soid, simple, decelerate, -^ mic. Lichenoides, Dill. Muse. p. 



545. Tuckerm. Syn. N. E. p. 72 ; Lich. exs. n. 46. 



Rocks. New Jersey (J. Bartram), Dillenius Muse. 1741. 

 Common, in the low country, throughout the northern Atlantic 

 States ; and southward, in the mountains, to Georgia (Ravenel) . 

 Shores of Lake Superior, Agassiz. Northward to Newfound- 

 land. The largest species known; the fronds exceeding at 



length nine inches in diameter, and the fruit now more than 



two lines, or four millim. The lichen is quite distinct from 



U. vellea. 



14. U. angulata, Tuckerm. ; thallus scarcely middling, one- 

 leaved, coriaceous, rigid, smooth ; from ashy- at length tawny - 

 brown, rendered purplish by a thin bloom; beneath black, 

 granulate, lacerate, and clothed at length more or less with 

 paler fibrils; apothecia small to middling-sized, appressed, an- 

 gulate-patellate, flattish, plicate, with a thick, persistent mar- 

 gin. Spores ellipsoid, simple, decolorate, ^ mic. Syn. N. 



Eng. p. 74. 



* Semitensis, Tuckerm. ; scarcely differing in the specimens 

 seen, except that the spores vary from simple and decolorate, 

 when they resemble those of U. angulata, to brown, and muri- 

 form multilocular (transverse series of spore-cells, 5-8; of 3 to 4 

 members, in the middle), measuring then |J mic. U. Semi- 

 tensis, Gen. p. 31. 



Rocks of the Pacific coast, a, maritime rocks, Monterey, 

 California (Menzies), Tuckerman 1. c. ]848. Observatory inlet, 



British Columbia, Herb. Hook. * Semitensis, further inland, 



Tosemite Valley, and elsewhere (Bolander), Tuckerman I. c. 



1872. Fronds, of neither lichen, surpassing two inches in 



diameter. The spore-history of * is important as illustrating 

 the view elsewhere taken by the author, of the inferior system- 

 atic value of merely gradal differences in spores. It was re- 

 marked (Lich. Calif, p. 7), that lichens which exhibit the ulti- 

 mate condition or grade of their type of spore, exhibit also 

 ideally, and in fact more or less, all the steps or grades in the 

 preceding process of evolution. This is fully seen in U. Semi- 

 tensis, which offers, in a full examination, simple, bilocular, and 

 quadrilocular spores with entire spore-cells, and then every step 

 beyond to perfectly muriform ones. And the simple spore of 



