so 
NEW BRITISH LICHENS. 
Lecanora lacustris. A peculiar species, comparable with V. 
discreta , Mtzl. 
In addition to the above, Nylander, in his appended observations, 
remarks also on some other British Lichens, as follows : — 
1. Lecidea delutula. Nyl.— This agrees in the structure and 
spores with L. Arnoldi { Kphb.), of which it may be a sub-species, 
but the thallus is greyish-green, very thin (at length rimose), the 
apothecia pale carneo-luteous, subbin ate, usually gyalectoid ; spores 
0*012-16 mm. long, 0*004-5 mm. thick. 
On moist siliceous ferruginous rocks. Kylemore. 
2. Lecidea thiopsora. Nyl. — In “ Flora,” 1876, p. 573. This 
is only a form of L. pulvinata , Tayl., with the thallus somewhat 
sulphureous. 
3. Opegrapha hysteriiformis. Nyl— This is scarcely more than 
a larger form of Op. atrula , Nyl., in ‘‘Flora,” 1877, p. 565. 
On schistose rocks. Kylemore. 
4. Opegrapha saxigena f. clarescens. Nyl. — Thallus whitish or 
greenish-white, very thin, continuous, apothecia usually smaller 
than in the type. 
On rocks. Klyemore(Larbalestier); also in Appin(Crombie), 1876. 
5. Verrucaria prominula* viridans. Nyl. — Thallus pale or 
greenish, thin, continuous, subrimulose ; spores 0*010-12 mm. 
long, 0*007-9 mm. thick. 
On maritime rocks, near Kylemore. 
VITRICOLE LICHENS AND THE SCHWENDENERIAN 
HYPOTHESIS. 
In the “ Flora,” 1879, pp. 303-4, Dr. Nylander has a note upon 
Vitricole Lichens, from which we give the following extract, which 
bears directly upon Schwendenerianism, and will, no doubt, be 
interesting to the readers of “ Grevillea,” under whose notice the 
subject in other aspects has recently been so lucidly brought by 
the Editor. 
“ After observing that he had already in the ‘ Flora,’ 1877, 
p. 356, and 1878, p. 247, stated that it was useless to study the 
germinations of Lichens from spores cultivated at home,* because 
in Nature itself not only the earliest stages of these germinations, 
but also the whole development of Lichens can readily be perceived 
on quartzose rocks and smooth bark of trees, f Nylander proceeds 
to notice that the same may still more easily be observed on glass 
which has been exposed for a long series of years in districts where 
Lichens are of common occurrence. “ There, in the very pure sur- 
* Vide also Cromb. in “Pop. Sc. Rev.,” 1874, pp. 267-8. 
+ To this also may be added, on mortar of walls and houses, as in the 
suburbs of London. — J. M. C. 
