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Carolina (Mr. Ravenel) and occurring also, rarely, on Beech trunks at 
“New Bedford (Mr. Willey) is readily distinguishable by its straw-coloured, 
granulose thallus, and no less by its quadrilocular spores; measuring 
0,012-0,016™™- in length, and 0,004-0,005™™- in width. —— We may conve- 
niently here notice, together, some species, either certainly or possibly 
parasitical on other lichens. Such plants have been little looked for in 
this country; and it is likely that there remain others to be detected, 
even in the present genus. ——B. saxatilis (Scher.) Kb. (Zw. exs.n. 140, 
Scher. Helv. n. 240) has been found on talcose schist and on limestone in 
Vermont (Mr. Frost). Thallus less developed, but not unlike that of the 
cited lichen of v. Zwackh; with which the American specimens appear 
to agree entirely in the apothecia, and spores. Nylander regards the 
plant ‘quasi myriocarpa ecrustacea’ (Scand. p. 237) inhabiting the thallus 
of other lichens ; in which case, the separation of the next species becomes 
questionable. —— B. inquilina, Tuck. (Lich. Calif. p. 82) is an inhabitant 
of the thallus and apothecia of normal conditions of Pertusaria, occur- 
ring in Pennsylvania, in North Carolina (Rev. Dr. Curtis) South Carolina 
(Mr. Ravenel) and Texas (Mr. Wright). Spores biscoctiform, bilocular, 
0,009-0,015™"- long, and 0,009-0,007™™- wide. —— B. parasitica (Floerk.) 
Th. Fr. (Nyl. Lich. Par. n. 68) has been found, within our limits, on 
Pilophorus acicularis, f. robustus, in islands of Behring’s Straits (Mr. 
Wright) and on the apothecia of Lecanora pallescens, v. corticola in Cali- 
fornia (Mr. Bolander).——A new, polysporous species, allied to the last, 
as to Lecid. glaucomaria, Nyl., but the spores from 35 to 50 in the thekes, 
has been detected by Mr. Willey on Pertusaria pertusa, saxicola, and 
will be described elsewhere. And the same lichenist finds on the crust 
of the Pertusaria, as on that of Lecanora tartarea, a parasitical Buellia 
still nearer to Lecid. glawcomaria; but I find no spores measuring more 
than 4238 micromill. ——Abrothallus Smithii, Tul. (Herb. Borr.) with sole- 
iform, bilocular spores, and found here on Parmelia sazxatilis and 
P. Borreri, is now excluded from Lichens. 
Thus far Hubuellia has afforded no other light on the process of 
differentiation of the brown spore, than the passage of the more common 
bilocular into quadrilocular (or, very rarely and exceptionally, plurilocu- 
lar) conditions. But we should not expect the evolution to stop here; 
and the next species may fairly be said to complete the history, and to 
mediate satisfactorily between the bi-quadrilocular B. parasema, and 
papillata, and the distinctly muriform-multilocular B. oidalea 
B. albo-atra (Hoftm., Nyl.) Th. Fr. Gen. (Zw. exs.n. 123. Fr. Lich. Suec. 
n. 413) the regularly quadrilocular spores of which soon exhibit plain 
indications of the next or muriform modification, is not uncommon, 
especially on Elm, in New England; asin New York (Mr. Willey) and 
Canada (Mr. Drummond) and was found by Mr. Wright, on 4 sculus, in 
California. The rupicoline state (v. saxicola, Fr.) occurs on lime-rocks, 
Kansas (Mr. Hall) and on the sandstone of the Connecticut valley, in 
