(113) 
whose name it bears.——L. gelida (L.) Ach., of the north of Europe, was 
found in Greenland by J. Vahl. (Th. Fr. Lich. Arct. p. 83).——L. thamno- 
placa, Tuckerm.! (a very marked representative of the olivaceous series) 
the adnate, lobulate thallus of which is in fact made up of short, closely 
crowded trunks, much as in L. rubina, v. complicata (Anz. Lich. Ital. 
n. 158) and should so far differ from LZ. Montagnei (Fr.) Scher., with 
which it agrees in a certain resemblance of the fruit to L. badia, is one of 
Mr. Bolander’s most recent discoveries, on the granitic rocks of Nevada. 
— L. rubina (Vill.) Ach. (ZL. chrysoleuca, Auctt.) is the type of an ele- 
gantly varied group of rock-lichens of the alpine regions of Europe, 
which, finding its centre of evolution here in the Organ mountains of 
Texas (Wright) and the Rocky Mountains (Hayden; E. Hall) extends 
northward even to Arctic America (Herb. Hook.) and descends thence to 
the northern shore of Lake Superior (Agassiz). Beside the more widely 
diffused monophylline condition, Mr. Wright collected in Texas the pale- 
fruited, peltate form of the south of Europe (Sgwamaria peltata, DC., 
Nyl.!) the bluish-black under side of which (hypothallus glaber, Fr.) is 
not only powdery, as Scherer (Spicil. p. 486) observed, but even, if I mis- 
take not, at length almost villous; and the still better marked and less 
ascendant, black-fruited v. opaca (S. melanophthalma, DC., Nyl.). Only 
an inferior (campestrian) state of this fine species, with short, erectish 
lobes crowded together so as to pass into gyrose plaits above, and always 
brown below, is known in New England and the adjacent regions. The 
related ZL. cartilaginea of the north of Europe, is quite unknown here. 
But its place is perhaps made up by L. Haydeni, Tuck. Obs. Lich. 1. c. 6, 
p. 267, with a still more distinctly subfoliaceous, convoluted thallus, 
occurring free, and ‘covering many square miles’ in the Laramie plains, 
Nebraska, where the wind heaps it even into drifts (Dr. Hayden). The 
fronds of this species are almost Parmeliine, and comparable with those 
of P. conspersa, but the texture is crustaceous; and LZ. rubina, to which 
it is nearest, varies in the same direction, and in its hypothallus still more 
conspicuously, from the family type. ——WL. muralis (Schreb.) Scher. 
(ZL. saxicola, Auctt.) is common throughout the United States, and passes, 
westward, into several marked varieties. One of these, and undoubtedly 
the noblest condition of the species, is undistinguishable from the var. 
Garovaglii, Anz. (Lich. Langob. n. 270) and has occurred here, in 
Nevada (Bolander); and another, calcareous form, perhaps scarcely 
1 Lecanora thamnoplaca (sp. nova) thallo ex areolis squamiformibus subinde 
crenatis turgidis, centro stipitatis, ambitu lobatis, pallide cervinis ; apotheciis 
(1—1,5™™- lat.) innato-superficialibus, disco rufo-nigro, margine demisso. Spore 
octone, ovoideo-ellipsoiden, simplices, incolores, longit. 0,009-16™™., crassit. 
0,005-8™™-. Nevada (Mr. Bolander). Thallus at length caulescent at the centre, 
the stout stipes, which are divided above, now exceeding 3™™- in height. I should 
compare this feature, generally, to the analogous modification of structure in 
Lecidea vesicularis. Spermogones not seen. 
15 
