(85) 
Of the group as here taken, about twenty-five species have been indi- 
cated; all but seven of them European. About one half inhabit the 
south of Germany, and Italy, two only of these reaching northward as 
far as Westphalia, and one, the neighbourhoods of Paris and Jena; four 
the south of France, of which two are also found in Algeria, and one 
in Algeria and Alabama; one is known only as Algerian; and one ranges 
from the middle of Europe to the Icy Sea, and, in America, from Rhode 
Island to Lake Superior, and doubtless northward. Beside the two, com- 
mon to North America and Europe, there is one American species peculiar 
as yet to Texas, and one to Alabama. Five tropical, American species 
are known, all of them from the island of Cuba. With the exception of 
O. phyllisca, the genus is almost wholly, though the rule is not quite 
without other exception, confined to calcareous rocks. 
O. Girardi, Dur. & Mont.,e Nyl. (Coll. plutonium, Tuck. in litt.). 
Lime-rocks in Northern Alabama (Mr. Peters). —— 0. pyrenoides, Nyl. 
On similar rocks in Texas (Mr. Wright). —— 0. wmbella, Tuck. in Nyl. 
Syn. (Collema, Nyl.). Lime-rocks in Northern Alabama (Mr. Peters). 
I find no important difference in thalline structure between this and O. 
botryosa, Nyl. (Plectopsora, Mass. Herb. Koerb.) and -the two plants 
are most closely akin; the apothecia of the latter being by no means 
always so inconspicuous or ‘endocarpeine’ as they are described. —— 0. 
phyllisca (Endocarpon , Wahl., Ach. Synalissa Fr. Omphalaria Deman- 
geonti, Mont. O. Silesiaca, Koerb. Phylliscum, Nyl.). Granitic rocks, 
White Mountains, (Mr. Russell). Vermont (Mr. Frost). Massachusetts 
(Mr. Willey). Rhode Island, (Mr. Bennett). Lake Superior (Prof. 
Agassiz). 
XXIV.—COLLEMA, (Hoffm.) Fr., Flot. 
Collema, Fr. 8. 0. V. p. 255. Flot. Collem. in Linnea, 1850. Mont. 
Aper¢. Morph. p. 12. Collema (C. saturn. excl.) Fr. Fl. Scan. p. 292; 
Summ. Veg. Scand. p. 121. Tuckerm. Syn. N. E. p. 89; Suppl. 2, 
l. c. p. 201; Obs. Lich. 1. c. 5, p. 385, et 6, p. 263. Collema max. p., 
Nyl. Prodr. p. 19; Syn. p. 101, t. 2, f. 3, t. 3, f. 1-6, t. 4, f. 6, 19-21, 
Lich. Scand. p. 28; in Prodr. Fl. N. Gran. p. 1; Syn. Lich. N. Caled. 
p. 4. Collematis spp., Schreb., Hoffm. D. Fl. 2, p. 98. Ach. L. U. p. 
129, 628; Syn. p. 308. Eschw. Syst. p. 20; in Fl. Bras. p. 231. Fée 
Ess. p. 66; Suppl. p. 127. Scher. Enum. p. 247. Parmeliz spp., 
Ach. Meth. p. 221. Mey. Entwick. Scher. Spicil. p. 511. Parmelia 
spp., et Patellarie spp., Wallr. Fl. Crypt. Germ. 1, p. 434, 545. Col- 
lema, Blennothallia, et Synechoblastus, Trevis. Lethagrium et Col- 
lema pr. p., Mass. Mem. p. 80, t. 13-17. Lempholemma, Synechoblas- 
tus, et Collema, Koerb. Syst. p. 400. Th. Fr. Lich. Arct. p. 276. 
Physma, Synechoblastus et Collema, Anz. Catal. Sondr. p. 2; Manip. 
l.c. p. 181. Stizenb. Beitr. lL c. p. 134. Physma, Lethagrium, et 
Collema, Krempelh. Lich. Bay. p. 90. Physma, Lethagrium, Synecho- 
