(118) 
from ZL. varia. Nor does ZL. melanaspis (Wahl.) Ach. (placed with 
L. circinata in his sect. Psora by Fries; and in similar relations both 
with the latter and with Aspicilia in Nyl. Scand. p. 162) diverge any 
more widely than in a better-developed thallus, and more superficial 
fruit ; the last varying indeed from the more innate type much as Urceo- 
lurvia ocellata from U. scruposa. But this sub-foliaceous overgrowth of 
Aspicilia (Alphoplacium, si placet; the analogue of Squamaria) passes 
also, in the curious free-lichens of the Siberian and other deserts, from 
a probably originally peltate, squamarieform condition (ZL. esculenta ; 
L. affinis) into a perfectly fruticulose one (L. fruticulosa, Eversm. ; 
Spherothallia, Fr. Nees pr. p., the analogue of Cladodium) a luxuriance 
suggested also by the isidioid thallus of LD. oculata. 
About thirty forms referable to this section as here taken, have been 
described, but the number of species is possibly much less; the extent of 
the group constituting L. cinerea being quite differently apprehended by 
different writers. With the exception of two or perhaps three (Nyl. 
Enum. Gén. p. 118) the species are all northern, and nearly all common 
to Europe and America.— LL. melanaspis (Wahl.) Ach., a, alphoplaca, 
Fr., has occurred in Greenland (J. Vahl, in Th. Fr. Lich. Arct. p. 82) but 
elsewhere, on this continent, only (on lime-rocks) in Kansas (E. Hall) 
and in the Yosemite Valley, California (H.N. Bolander). JL. circinata, 
Ach., though a northern lichen, is yet quite unknown as North American. 
——L. cinerea is by no means less diversified here than in Europe; and 
if Gyalecta odora (occurring with us on granitic rocks) be to be added, as 
by Koerber, and by Nylander, to the series of forms explainable by it, — 
fairly reaches over into the next succeeding sub-family.—Both the ter- 
ricoline species of Europe — LZ. verrucosa (Ach.) Laur., and L. oculata 
(Dicks.) Ach., are natives of Arctic America; and the former has also 
occurred in the Yo Semite valley, California (Afr. Bolander). And it is 
observable in this connection, that Pertusaria glomerata, the companion, 
in other countries, of L. verrucosa, is far from rare in the alpine regions 
of New England.—L. glaucomela, Tuckerm.,' from California, is rather 
a sub-species, to be arranged under L. ocudlata. 
The stress of difference in the last group (Aspicilia) is on the concay- 
1 Lecanora glaucomela (subsp. nova) thallo crustaceo eartilagineo primitus 
contiguo levigato glaucescente ; apotheciis (1—1,5™™- lat.) sessilibus planis, mar- 
gine thallino erenulato discum nigrum submarginatum vix superante. Spore in 
thecis lingulaformibus octone, ellipsoidec, simplices, lato-limbate, longit. 0,018 — 
21™™., crassit. 0,009 —14™™., paraphysibus filifor mibus-——On the branches of 
Abies muricata, California (Mr. Bolander). Spermatia staff-shaped; sterigmas 
simple. Only the thekes shewing the blue reaction with iodine. The spores 
(rather smaller than those of L. oculuta) always disposed in a single series in the 
strap-shaped thekes. The species of which I suppose this to be a form, and which 
is remarkable for its branched thallus, is unknown as yet in Western America 
south of the arctic zone. 
