306 DR. LINDSAY ON WEST-GREENLAND LICHENS. 
gattet) lat. 70° 2 30” N., long. 52 W. (approx.); the chief site of the fossil (Miocene) 
plant-beds. 
The principal rocks on which the sawicolous lichens occur are granite, gneiss, and 
trap; while terricolous forms affect a soil consisting of the débris of these rocks.  Cor- 
ticolous species were found mostly on twigs or stems of birch bushes * ; while muscico- 
lous forms chiefly frequent Rhacomitrium lanuginosum t, a moss that appears to be abun- 
dant in all northern countries 1. 
In the examination of the present collection of Greenland lichens, I have made use of 
the chemical tests recommended of late years by Nylander and Leighton as a means of 
determining lichen-species. All the positive results—all instances of reaction of a 
marked kind—are hereinafter recorded. In the majority of cases, however, there was no 
reaction, or none of a kind meriting record; while in species in which a decided reac- 
tion was sometimes exhibited, at other times it was obscure or absent. In other 
words, reaction was, in these exceptional cases, capricious or inconstant. Hence the 
result of the present comparatively limited series of testings only confirms that of 
the more comprehensive series of experiments described in a former memoir to this 
Society $. 
The present collection contains only one strictly arctic lichen, Dactylina arctica. 
But it contains several lichens that are apparently new, inasmuch as I cannot refer 
them to any of the species or varieties described in Th. M. Fries's * Lichenes Arctoi Eu- 
rope Groenlandiseque,’ in his *Lichenes Spitsbergenses, in Nylander's ‘ Lichenes 
Scandinavie,’ in the various monographs on arctic lichens scattered through botanical 
serials to which I have had access; or to the specimens contained in the various public 
or private herbaria I have examined ||. 
These new forms are mostly referable to the genus Lecidea, viz. :—L. Grenlandica, 
L. Campsteriana, L. Friesiana, L. Egedeana, L. Discóensis, L. Vahliana. But they 
represent also several other genera or pseudo-genera, viz. :— Pertusaria paradoxa, Ver- 
rucaria tartaricola, V. Campsteriana. 
There are, moreover, various parasites—micro-fungi or micro-lichens, or their isolated 
pycnidia or spermogonia—to which I have not thought it proper at present to assign 
distinctive names. 
The main interest of the collection attaches, however, not to the character or number 
of the apparently novel forms it contributes to science, but to the illustrations which 
it offers of the following, among other, characteristies or peculiarities of extreme north- 
ern, aretie, or alpine lichens, viz. the frequency of occurrence of :— 
1, Parasitic Micro-Fungi or Micro-Lichens, or their separate pycnidia or spermo- 
gonia, affecting either the thallus or apothecia of the host, or both. 
* Betula nana, L. + Or a moss closely resembling it. 
+ Thus I have pointed out its abundance in Iceland and Norway: *Flora of Ieeland,' p. 23, Edinb. New Philos. 
Journal, July 1861; ‘ Lichen-flora of Northern Europe, p. 406, Journal of Linn. Society, Botany, vol. ix. 
$ ‘On Chemical Reaction as a Specific Character in Lichens, Journal of Linn. Society, Botany, vol. xi. p. 36. 
Vide also Trans. Botan. Soc. Edinb., vol. x. p. 82. 
| There were (in 1858) few Greenland lichens in the Kew Herbarium ; and none in the Herbaria of Linnzus in 
the Linnean Society, nor in that of the University of Edinburgh. 
