(186 ) 
(Lecidea Wahlenbergii, Ach.) isanative of arctic America (Hook.). The 
plant of the White Mountains referred here, seems possibly a depauperate 
state, but has never occurred fertile. B. scabrosa (Ach.) Koerb., 
growing very commonly in Europe on the thallus of Beomyces byssoides, 
has escaped me, if it occur, in our mountains; but is found in Greenland 
(J. Vahl, e Th. Fr. 1.¢.). Fries associated this lichen with the species 
next preceding; and Nylander has recognized the same affinity ; but the 
evidence of lobation, now obscure enough in that, quite disappears here. 
Of Eubuellia, as here constituted, and reckoning the species accord- 
ing to Nylander’s limitation of them, which differs very considerably from 
that of other writers of whose estimates I have availed myself above, 
two-thirds are known as North American. ——B. lactea (Mass.) Koerb., 
well marked by its many-angled, white areoles, imposed upon, and the 
whole often bordered by a conspicuous, blackish hypothallus, is common 
on granitic and other rocks, throughout the Appalachian mountain- 
system, reaching to Tennessee and Georgia (Mr. Ravenel) and is common 
also in California (Bolander). Lecid. lepidastra, Tuck. (Suppl. 1. c. p. 429) 
offers flat, dilated, crenulate and squamaceous areoles, and no trace 
of the dark hypothallus of B. lactea ; but the microscopical characters of 
the two scarcely differ; and, in view of the instructive series of forms of 
the European lichen published by Massalongo and Anzi, it is certainly 
less easy to keep our plant apart. ——B. stellulata (Tayl. in Mack. Fl. 
Hib. Nyl. Lich. And. Boliv. Herb. Borr. Herb. Lindig, 2, n. 156) looks 
like a very minute form of the last species. It has occurred on sand- 
stone in California (Mr. Bolander) and on trap rocks in New Jersey 
(Mr. Austin). Spores 0,007-0,013™™- long, and 0,004-0,007™™- wide. —— 
B. atro-alba (Flot.) Th. Fr. (Fr. Lich. Suec. n. 382) has probably the same 
range with B. lactea, but is more easily passed over. It is common in 
New England; and I have it from Pennsylvania (Dr. Michener) and the 
mountains of Virginia (Rev. Dr. Curtis). In the var. chlorospora, Nyl. 
(deterne. ipso) which is common in our mountains, the spores are colourless 
and thus constitute Catillaria, at least of Anzi, with whom this name 
designates only a section of Buellia. —-B. pullata, Tuck. (Lich. Calif. 
p. 26). Sandstone rocks, California (Mr. Bolander). Areoles squama- 
ceous. Spores 0,012-0,018™™- long, and 0,005-0,009™™- wide.——B. coracina 
(Moug.) Th. Fr. (Lecidea, Moug. & Nestl. n. 462. Nyl.in Fellm. Lich. 
Arct. n. 193) remarkably conditioned by the predominant, black hypo- 
thallus, and interesting also as affording an example of very commonly 
simple (mature) spores—a condition as rare in the coloured as it is com- 
mon in the colourless series—is abundant in the alpine region of the 
White Mountains; and was brought from arctic America by Dr. Kane. 
——B. halonia (Ach.) a Cape of Good Hope rock-lichen, with an areolate, 
greenish-yellow thallus, of which excellent specimens were collected by 
Mr. Wright (N. Pacif. Expl. Exp.) has occurred also on the coast of 
California (Mr. Bolander). —B. papillata (Sommerf.) (B. insignis, Th. 
