304 REVISION OF THE BRITISH COLLEMACEI. 
lobes of the thallus larger, rare at Killarney. Sp. 12. C. jie sum, 
Ach., easily recognised from the allied species by the adglutinated 
evanescent thallus, and the appressed thinly- -margined apothecia, no 
doubt frequently overlooked, at least in S. England. Sp, 18.C. ertspum 
(Huds.), probably not uncommon, though the true plant is but rarely 
seen in hob. Var. 1. eristatulum, Nyl., eas ily recognised by the 
microphylloid thallus, Gomnrne in the Channel Islands and probably 
also in S. England. Sp. 14. C. cheileum, Ach., common where it- 
parently rare, as at Killin and in 8. Ireland. F. 2. monocarpon (Dut.), 
with microphylline or nearly obliterated thallus, near Cirencester, and 
probably overlooked elsewhere. Sp.15. C. melenum, Ach,, a common 
and rather variable species, of which the following forms are sparingly 
found in Britain and Ireland. F.1. marginale (Huds. ) probably not 
very uncommon, though not sufficiently distinguished im more recen nt 
hbb. from the type. F. 2. jacobeifolium ges gt Agia 
rare in the Channel Islands and in 8.W. Ireland 3. gyrosum, 
Ach., seen by us very sparingly on Craig Teallock, and only @ 
few old apothecia present on the specimen gathes ed. F ompli- 
England and theS. W. Highlands. Alltheseforms appear to be connected 
by intermediate states, some of which can with difficulty be referred 
to any - them in particular. - Sp. 16. C. cristatum (Hffm.), Scher, 
differs from the preceding, though perhaps only as a subspecies, in the. 
Sniluieadaragare gated lacinie, and the slightly different character of 
th ores, probably not very rare in upland tracts, though | 
recently overlooked as a British plant. Sp. 17. C. polycarpon 
on Cheddar Cliffs, near Kendal ea at Appin. 
D. Lathagrium (Ach.). a. stirps C. flaceidi. 
Sp. 18. C. stygium (Del.), similar to the preceding port but 
with 3-5-septate spores, rare as near Cirencester, Ken and in 
Teesdale. Sp. 19. C. Laurert (Fw. Krb. ds dninguihe et having 
the thallus broader, and the spores 8-septate, and obtuse at either 
apex, but apparently a somewhat doubtful British Lichen . 20, 
ak old walls _and trunks of trees, but very © bane seen in frult. 
up. 
( pr Taylan) i in 8.W. Ireland about Dunkerr on. 
b. stirps C. nigrescentis. - @. 
Sp. 23. C. nigrescens (Huds.) Hudson has priority of name 
Angl, ai i. p. 450), otherwise the more expressive one of Lightfoot 
might have been palpptets and the plant been called Collema Ve a 
(Lghft.) Sp. 24. C. aggregatum (Ach.), a very rare spe 
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