DR. LINDSAY ON WEST-GREENLAND LICHENS. 311 
ceous states are associated with similar, very deformed, dwarf, ventricose or Pycno- 
thelioid conditions of Cladonia amaurocrea. 
A specimen in the Kew Herbarium from Disco (Lyall, 1852), labelled fragile by Ny- 
lander, is simply a short, ceespitose, sterile form of coralloides. 
With iodine the white medullary tissue of passage-forms into compressum give, even in 
the same specimen, either no reaction, a pale violet, or a distinct blue. I have tried the 
effect of a diluted tincture of iodine on many specimens of $. coralloides, fragile, and 
compressum, from different parts of the world, collected at different times, and I am 
satisfied of its uselessness as a specific test. The reaction is both slow and difficult to ob- 
tain—where it occurs at all; for it is sometimes absent. It is quite capricious, therefore, 
being only sometimes violet or blue. With bleaching solution the medullary tissue of 
coralloides gives a brownish or blood-red colour like that of Lecanora tartarea under the 
same reagent; or this reaction is faint; or no reaction occurs; or colour is exhibited only 
in the dwarf, dense, subisidioid forms. For the development of reaction at all, the 
cortical layer must be bruised, and the medullary tissue exposed, by rubbing or break- 
ing up the former, when moistened, with the stirrer. 
Genus 5. CLADONIA. 
1. C. alcicornis, Flk.—Jakobshayn, intermixed with various mosses ; occurs sparingly. 
Under surface very white, with incurved margins. As in cervicornis, the folioles are 
sometimes very densely tufted, forming spherical masses. The podetia are very short, 
deformed, and inconspicuous, seated barrelwise on the folioles. The same black, puncti- 
form parasite that infests cervicornis grows on the podetia, and sometimes on the under 
surface of the folioles, of alcicornis. 
I regard alcicornis, as I do also cervicornis, as non-autonomous, but as mere condi- 
tions of Cladonie in which the horizontal foliaceous thallus is developed disproportionately 
to the podetia, Aleicornis passes, on the one hand, into cervicornis, and on the other into 
endiviæfolia *, these three so-called species differing only in the size of the thalline divi- 
sions. According to the latest (chemical) classification of Leighton and Nylander, cervi- 
cornis holds, however, position as a separate species t ; while it has been hitherto generally 
assigned to verticillata as a variety. Coemans has shown that, even by so distinguished 
a lichenographer as Acharius, alcicornis was confounded not only with cervicornis, but 
with pungens, degenerans, and pyxidata. Some of its forms (e. y. in the Menziesian Her- 
barium +) I have been enabled to refer to pysidata. In Leighton's Exs. no. 15, I found 
parasitic pycnidia on alcicornis—as described in my ‘Mem. Spermog.’ (p. 161). 
2. Q. cervicornis, Ach.—Jakobshavn, terricolous. Podetia and underside of folioles 
studded over with a black punctiform parasite. Upper surface of folioles becomes 
bright lemon-yellow with Liquor potasse, while underside exhibits no reaction. The 
* Coemans makes endiviæfolia a var. of — while other lichenologists have done just the reverse, regarding 
alcicornis as a var. of endiviæfolia ! 
T A position also assigned by them to Cl. cornuta, L., degenerans, Flk., fimbriata, Hffm., crispata, Ach., and ecmo- 
cyna, Ach., all of which I hold to be mere conditions or forms of other species. 
+ Contained in the Herbarium Hall of the Royal Botanic Garden, Edinburgh. 
