362 DR. LINDSAY ON WEST-GREENLAND LICHENS. 
from the pressure of the contained sporidia; they are 0018" long and :0006" broad. The 
hymenial gelatine always gives a blue with iodine, varying, however, in tint, pale in 
Illartlek forms—dark Prussian blue in those from Lyngemarken. In the latter forms, 
paraphyses, asci, and sporidia are all indistinct. In other forms, the constituents of the 
hymenium are also indistinct. In some cases the tips of the paraphyses are very deep 
brown: more generally they are pale brown and agglutinated. The section of the hy- 
menium under the action of iodine is sometimes a beautiful microscopic object, e. y. in 
the Lyngemarken forms. 
The sporidia of vernalis, as defined by N ylander (Scand. p. 201), are simple or 2-locular * ; 
and I have frequently met with British lichens, referable, I think, to vernalis, whose 
sporidia are variable in their structure. But the present rigid system of classification, 
according to the character of the sporidia, places those forms with simple sporidia in 
Biatora, and those having 2-locular ones in Biatorina! This is only one of many illus- 
trations that may be cited to show the awkwardness and arbitrary character of the too 
elaborate generic distinctions of modern systematists! Th. Fries himself remarks upon 
the multiplicity of forms included under vernalis, and the repulsive confusion of its nomen- 
clature or synonymy. 
Genus 20. NORMANDINA. 
1. N. viridis, Ach. —Lyngemarken. Sterile as usual. Thallus covered with a ver- 
milion-red, roe-like powder or granular matter, having the characters of soredia, and con- 
taining gonidia of the normal type. Both genus and species occupy a position in relation 
to Cladonia as provisional and anomalous as that of Thamnolia vermicularis. The apo- 
thecia of the Normandina are unknown. Fries, father and son, are disposed to refer it 
to Cladonia; but its thallus is much more delicate than the phyllocladia of that genus 
usually are, while it differs also in its concentric striation or banding. By other authors 
it is associated with N. Jungermannie, which has endocarpoid apothecia. 
Pseudo-genus 21. PYRENOTHEA. 
1. P. grenlandica, n. sp. Consists only of spermogonia, which therefore cannot be 
referred to the species to which they must belong. The thallus is olive-coloured and 
verrucæform. The spermogonia are perched on the apices of the thalline verrucæ ; they 
are always black and conspicuous, but they vary considerably in size and form. They 
are mostly small and papillar, but sometimes large and discoid, having quite the aspect of 
some lecideoid apothecia. The outline of these flattish, large, discoid forms is generally 
more or less irregular. The spermatia are apparently straight rods seated on sterigmata, 
which consist of only two or three linear simple articulations. 
The plant has various of the characters of the British P. corrugata (as regards its 
perithecia), of P. sulphurea and P. lithina (as respects its thallus). The two latter are 
probably referable to Verrucaria chlorotica, Ach. (=trachona, Ach.), which, however, does 
* Thus they are both simple and 2-locular in an athalline form which grows on the decayed thallus of various 
Peltidee. 
