340 DR. LINDSAY ON WEST-GREENLAND LICHENS. 
in his * L. Arctoi”) and other Continental authors, such as Kórber, Stizenberger, and 
Massalongo, appears to me to be unscientifie, inasmuch as their characters are not con- 
stant—and unnecessary, inasmuch as it is sufficient for the purposes of classification to 
give them place (if separate place they ought to have) as sections only. The following 
subgenera, however, made use of by Th. Fries, in his * L. Arctoi,’ being those only that 
are represented in Greenland, suffice to illustrate their very arbitrary definitions :— 
(1.) Caloplaca, Th. Fries. Sporidia ellipsoid, colourless, polari-bilocular. 
(2.) Dimerospora, Th. Fries. Sporidia oblong, 2-locular, colourless. 
(3.) Rinodina, Mass. Sporidia 2-locular, brown. 
(4.) Dimelena, Norm., emend. Sporidia 8, 2-locular, biscoctiform, brown. 
(5.) Hematomma, Mass. Sporidia acicular, 5- to poly-loeular, hyaline. 
(6.) Gyalecta, Ach., emend.  Sporidia ovoid-oblong, or fusiform, 4- or multi-locular, 
colourless. | 
(7) Aspicilia, Mass. Sporidia simple, colourless, ellipsoid. | 
(8.) Acarospora, Mass. Sporidia myriad, very minute, simple, hyaline. His true genus 
(9.) Lecanora, includes species referable to the following genera or subgenera :— 
Ochrolechia, Cryptolechia, and Lecanidium of Massalongo ; Polyzosia and Zeora 
of Kórber. 
1. L. tartarea, L.—Jakobshavn ; Godhavn, fruit abundant; Lyngemarken, apothecia 
compound; Illartlek Glacier, in fruit. One of the most abundant lichens in the area 
examined by Brown. Especially common in its muscicolous forms, which include 
frigida, Sw.; gonatodes, Ach.; grandinosa, Ach.*; and thelephoroides, Th. Fries (L. 
Spitsberg. p. 21). Though frequently fertile as to apothecia, it is more generally sterile, 
the thallus occurring in an abortive or degenerate condition. This sterile thallus is very 
common, covering large patches of dry, decayed vegetation, mostly mosses. In its 
earliest stage of development, the thallus appears as a thin, very white, effuse, smooth 
coating. Next, wartlets gradually become developed here and there; these gradually 
multiply and coalesce into a tartareous thallus; and lastly the spicula (which are 
typical in gonatodes) are exhibited. Sometimes the thallus forms large loose erusts on 
mosses, having little hold, and being therefore easily detachable in patches, which have 
the appearance of rough plaster moulds of the subjacent decayed vegetation. Frequently 
the sterile thallus is sorediiferous, less often isidioid. Though generally white, especially 
in the young state, the colour varies to tawny yellow. These cream- or buff-coloured 
forms are more frequently uniformly granular than verrucæform, and are very different 
from the ordinary verrucose thallus of the type. They give, however, the same beautiful 
blood-red reaction with bleaching-solution, and are so frequently and intimately asso- 
ciated with the more usual conditions of tartarea, that they too appear to be referable 
to it. Sorediiferous forms have frequently a greenish tint, probably from growing in 
the shade. Occasionally there is apparently no filmy or rudimentary stage, or prothallus— 
the earliest form of thallus consisting of a series of smooth subspherical warts, scattered 
irregularly over the surface of herbage, varying greatly in size, frequently agglomerated 
- * Not mentioned as a Greenland form by Th. Fries in his * L. Arct? p. 100. 
