DR. LINDSAY ON WEST-GREENLAND LICHENS. 343 
which developes a blue colour in the hymenial gelatine. The sporidia are fusiform or 
ellipsoid, varying considerably in all dimensions; usually about -0006” long, and 00015" . 
broad, 3- to 6-locular. Within the asci the loculi of the sporidia sometimes resemble 
rows of button-like nuclei, subspherical or transversely oblong. According to prevalent 
rules or customs as to botanical nomenclature and classification, this parasite appears 
to require a separate place or name, at least provisionally. I therefore distinguish it from 
V. tartaricola as VERRUCARIA CAMPSTERIANA *, 
On some Greenland forms of var. frigida occurs still another parasite, as very minute, 
black, punctiform, erowded perithecia, full of round, brown or olive, simple, usually gra- 
nular spores, varying from :00009" to :00022” in diameter, partly cohering in large irre- 
gular masses, partly having the appearance of Torula spores. 
2. L. parella, L. Kudlesæt, on willow- and Betula-stems and leaves, decayed and 
dry; also muscicolous. Some of its forms have the characters of upsaliensis, others of 
| var. frigida of L. tartarea. It is obvious that the one variety passes into the other, just 
as do the typest. 1 have long been of opinion that tartarea and parella belong properly 
to a single type, and cannot be specifically separated. I have met with innumerable 
passage-forms from very different parts of the world, but especially from alpine and 
aretie regions. In many cases I have found it impossible to refer individual specimens 
to the one plant or variety rather than to the other. But such difficulties are obviated 
by uniting tartarea and parella and abolishing separate names for varieties, which are 
mere inconstant states of growth, depending on the nature of the habitat (e. g. whether 
rock or stone, wood, leaves, or moss). Upsaliensis gives no reaction with bleaching-solu- 
tion. But after all I have elsewhere said} of the capriciousness of this reaction in 
lichens, and particularly in Z. tartarea, it would be obviously absurd to make its pre- 
sence or absence a character for separating or establishing species. 
3. L. oculata, Dicks. Illartlek glacier, terricolous, with quite the characters of the 
British Isidium oculatum, Dicks. (E. Bot. t. 2267). It also occurs corticolous on birch- 
bark, associated with L. tartarea. The young thallus is exactly like that of L. tartarea, 
coating leaves and mosses with a very vividly white crust, The mature state exhibits 
a series of beautiful tall, white, thick pillars, resembling greatly magnified isidia, digitately 
branching below their tips, which are subdiscoid. These pseudo-disks have a darker 
shade of colour than their thalline margin, An intermediate condition between these 
two states of thallus, the typical young and the typical old ones, resembles the dwarf, 
compact form of Spherophoron coralloides, with which it is apt at first sight to be con- 
founded. Here the podetia-like columns are very short and stunted, closely arranged, 
producing a subtartareous thallus. But the columns are always very fragile and spongy, 
occupied by a light, soft, cottony tissue; whereas the branchlets of Spherophoron are always 
comparatively tough. The plant appears to be generally sterile in Greenland, as it is also 
* Vide Lecidea Campsteriana for origin of the specific name. 
t In Hepp's Exs. No. 673, L. pallescens, var. vpsaliensis is quite the frigida var. of tartarea, except as to the 
colour of the disk. 
+ “On Chemical Reaction as a Specific Character in Lichens," Journal of Linnean Society, vol. xi. Botany, p. 36; 
and Trans. Botanical Society of Edinburgh, vol. x. p. 82. 
