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especially in the hirsute under side, compares at length closely with 
Umbilicaria hirsuta. 
In other species which agree with the preceding in the gonidia, and 
the spores, and, so far as these are known, in the spermogones and their 
contents, the thallus is reduced, and becomes at length squamulose, and 
finally semi-crustaceous. But this reduction is lessmarked in EZ. arboreum, 
Schwein. (EZ. Tuckermani, Mont., Raven.) which though agreeing with 
the others following in being attached generally by a (here conspicuous) 
blackening hypothallus, is yet truly foliaceous and compared by Fries 
(L. E. p. 407) with a ‘Sticta haud rite evoluta.” The species was first 
detected at the South (Schweinitz) where Mr. Ravenel has especially 
elucidated its variations; but is common also, and equally fine, on old 
trees at the North. The last species is closely related to E. rufescens, 
Ach., growing on the earth, in Texas (Mr. Wright) New Mexico (Mr. 
Fendler) and in the Rocky Mountains (Dr. Hayden).——And EL. rufescens 
is itself so near to E. hepaticum, Ach., occurring in similar habitats to the 
other, and from Greenland (Vahl, in Th. Fr. 1. c.) to New England; New 
Jersey (Mr. Austin) Illinois and Kansas (Mr. Hall) and New Mexico 
(Mr. Fendler) that authors only distinguish the last by its smaller, darker, 
and commonly thinner fronds; and rather smaller spores. 
More distinct is #. cinereuwm, Pers., differing also from the other species 
preceding in its simple (not jointed) sterigmas; by which character 
Nylander excludes as well this as the next from Endocarpon, and asso- 
ciates them with his Verrucaria. EE. cinereum, v. cartilagineum, Nyl. 
(Z. dedaleum, Krempelh.) is an earth lichen, which has occurred in 
Greenland (Vahl, e Th. Fr. 1. c.) and, in a state scarcely distinguishable, 
in the Yosemite valley, California (Mr. Bolander). We have here another 
example of the peculiarly limited distribution of certain common European 
lichens, in this continent. ——. ochroleucum, Tuckerm.,' a rupicoline 
lichen, which admits of some comparison, as respects general habit apart 
from colour, with Z. Schereri (Fr.) (E. miniatum v. monstrosum, Scher.). 
The latter is however made up of peltate squamules; and our plant, 
which has occurred only on the coast of California (Mr. Bolander) consists 
rather of stipitate areoles. The bearing of the nigrescent spores of this 
species on the question, above touched upon, of the distinction by its 
1 Endocarpon ochroleucum (sp. nova) thallo areolato-diffracto crasso flavo- 
virescente, areolis confertis turgescentibus lavigatis, centralibus substipitatis, peri- 
phericis lobulatis ; apotheciis immersis, perithecio atro, amphithecio nigricante. 
Spore in thecis lanceolatis 6-8ne, cymbiformes, biloculares loculis approximatis, 
dilute nigro-fuscescentes, longit. 0,018-26™™- crassit. 0,0035-55™™-. —— On serpen- 
tine, Mendocino county, California (Mr. Bolander). Areoles small, the central ones 
not much exceeding, at the summits, 1™™-in diameter; but these, or several of 
them together, are prolonged downwards into thick stipes reaching 2™™- in height. 
Spores sub-fusiform, longer and narrower than those of EZ. Custnani, Mass. (Hepp. 
n. 669) but of similar structure. Spermogones not observed. 
