REVISION OF THE BRITISH COLLEMACEI. 335 
es. ce we have gathered it algo very sparingly near Tun- 
bridge W: 
z Pasta liglie Cromb. = stirps 0. microphylli. 
In section the thallus is nearly as in Leptogium, but t 
iS ecia’e are those of Collema, so that it forms a natural ei 
t 2 « U 
e follo genus. 
biatorinum, Nyl.—Pretty generally joie a in §. and W. Eng: 
land, but chiefly in chalk districts. Sp. 2 C. microphyllum, A: 
occurs chiefly on old elms in S. Roeland, ‘and frequently appears in 
b. 8.2. C. fragrans (Sm.) 
. Leptogium, Ach. To the species which, on a more accurate 
examination of the structure of the tha llus, have from time to time 
been removed from Collema to the present genus, others have now to 
be added. 
A. Euleptogium, Cromb. a. stirps L. tenwissimt. 
Sp. 1. L. amphineum, Ach.—Will no doubt be found elsewhere in 
England, as, being a rather inconspicuous plant, it may readily 
ther. 2. 
more obscure state, which originally was named by Nylander Collema 
psorellum. Sp. 3. ‘t prea (Deks.) = L. es ». yl. (not 
tenuissimum, Scand., p. 84), by no means a common British lichen, 
and apparently always very sparingly where it does occur. 
b. stirps L. eretacet. 
Sp. 4. L. fragile (Tayl.) _ sp Irish species is externally 
somewhat similar  Collema —s artitum, 
but the character of the aoreoal etiam ist of t. the ecia is 
Widely different. Sp. 5. L. eretaceum (Sm.) Unquestionably a very 
rare British species, an “extensive search over various of the chalk 
the thallus almost as in section E. of the preceding genus, dis- 
tinguished from Collena nana by the thalline exciple and the 
character of the spore 
c. stirps L. tremelloidis. 
Sp. 7. L. laceru ne (oe ), generally distributed, but by no means com- 
as in fructification. | F. 1, jimbriatim sei probably not very rare, 
butscarce ck ita (Hoffm ), 
hau 
most frequently fruited in the §.W. Highlands. Var. 
(Ach.), occurs also sparingly in the Chisinel Islands. Van tenuisst- 
mum, Nyl., will no doubt also be detected in this country, and indeed 
Tie, Bees a specimen from Appin which, except in a slight ee 
the size of the spores, seems § ufficiently identical. 
— subtile (Schrad. ) evidently a rare British plant, which must beacadiity 
be disti guished from L. tenwissimum, and all the somewhat similar 
of the preceding species. Sp. 9. L. sinuatum n (Hluds.), chiefly 
