DR. LINDSAY ON WEST-GREENLAND LICHENS. 319 
Finmark,—as well as of a parasitic Spheria, which may appropriately bear the provisional 
name, S. stereocaulorum, Th. Fries (L. Spits. p. 30). The Biatorina occurs also in Spitz- 
bergen on S. denudatum, Flk. 
Gen. 7. THAMNOLIA. 
- 1. T. vermicularis, Sw.—Jakobshavn. Erect forms : terminate frequently in a curling 
horn. Podetia also marked by various horn-like offshoots, especially towards their tips, 
which are sometimes ramose. Warts are also numerous, but show no special structure ; 
. they appear to be merely rudimentary offshoots. There are numerous short, thick, or broad 
deformed conditions, comparable with Hepp's Exs. no. 298. All are hollow and very 
white, much whiter than any Cladonia, resembling somewhat macaroni, With potash, 
the thallus gives a lemon-yellow reaction. Some specimens show distinctly circumscribed, 
discoloured patches, which are copiously studded over with very minute, black, im- 
mersed, sporidiiferous perithecia. The asci, when isolated, are very beautiful microscopic 
objects; 8-spored, :0024" long and :0006" broad, giving no blue with iodine. Para- 
physes filiform, wavy, very delicate, tips not knobbed nor coloured, but as in Verrucaria. 
Sporidia, when mature, are brown or olive, bilocular and soleaform : :00045” to :00060” 
long and :00020” broad. In the young state they are ellipsoid, olive, and simple ; some- 
times, while in the asci, they are 1-septate (or 2-locular) and colourless. They are usually 
associated with much oily matter, in the form of globules. The perithecia in question 
appear to be parasitic. They agree with what I have already elsewhere described and : 
figured as Microthelia vermicularia*. 
Seattered on some of the podetia, but not on special portions of the cortical layer, are 
similar black punctiform perithecia, considerably larger than those of the Microthelia. 
They are spermogonia, probably, like the microthelia, parasitic, and perhaps referable to 
it. Their envelope is composed of dark brown, cellular tissue ; and they contain hosts of 
straight, rod-shaped spermatia, :00015” long. They do not correspond in characters 
either with the spermogonia formerly described by myself as occurring in 7. vermicula- 
ris t, or with those described by Nylander i. 
There is the utmost difference of opinion as to the true character and affinities of the 
genus Thamnolia, and as to the relation to it of the sporidiiferous and spermatiferous 
perithecia which oceur on its surface. Th. Fries (L. Arct.) classes T. vermicularis with 
Dufourea arctica as a Cladonia of which, he says, the apothecia have not yet been 
' discovered. Some authors separate Lichen tauricus, Wulf, as a species. It is said to 
have been found fertile by Floderus, in Œland, in 1853, the apothecia having been 
terminal and those of a Cladonia (teste Th. Fries, L. Arct. p. 161). The apothecia of ver- 
micularis itself, however, are described by Massalongo in the * Flora ' (1866) as belonging 
to the Cladonia group; and Kórber also describes them in his * Parerga ' (p. 14), appa- 
* Memoir on Spermogones, p. 528, pl. v. figs. 19, 24; and “Otago Lichens and Fungi,” Trans. Royal Society 
of Edinburgh, vol. xxiv. p. 441. \ 
+ Mem. Spermog. p. 143, pl. v. figs. 20-23. Compare the spermogonia of Beomyces, ‘ Mem. spermog. pp. | 
143-145. 
+ Th. Fries describes its spermogonia in his * Lich. Spitsberg.’ p. 31. 
