92 
W. Watson. 
saxieolous forms, the oak-woods by those bryophytes which prefer 
a sandy or a peaty soil, whilst in the oak-hazel-woods plants 
preferring a stiff soil are found. The amount of moisture present 
in these woods varies, but, as a rule, the oak-hazel-coppice has the 
greatest amount; the woods of the oak-type are of a fairly dry 
character, especially in upland situations, whilst the ash-woods of 
the uplands are the driest, those of the lower elevations approaching 
more closely to the oak-hazel in this respect. 
The following lists are useful for comparing the different 
associations. The naming of the species in all cases is taken from 
the Census Catalogues of the Moss Exchange Club 1 . 
(1) . The following species are abundant in all the three types 
of woods :— Catharinea uudulata, Dicranum scoparium, Mnium undil¬ 
lation, Neckera coiuplanata, Porojrichum alopecurum, Thuidium 
tamariscinuni, Brachythecium rutabulum, Eurynchium striatum, Plagio- 
thecium silvaticum, Hypnuin cupressiforme and its varieties filiforme 
and ericetorum, Plagiochila asplenioides and Lophocolea cuspidata. 
(2) . In the ash and oak-hazel-woods the following species, 
which are absent or of less frequent occurrence in the oak-woods, 
are found :— Hypnum molluscum, H. cuspidatum, Eurynchium rusci- 
forme, Camptothecium sericeum, Anomodon viticulosus, Mnium stellare, 
Bryum capillare (ground form), Encalypta streptocarpa, Fissidens 
viridulus and Radula coiuplanata. 
(3) . The following species are characteristic of the ash-woods:— 
Hypnum molluscum (dominant), H. cuspidatum, Eurynchium striatum 
(sub-dominant), Camptothecium sericeum, Anomodon viticulosus, 
Mnium punctatum, M. affine, M. cuspidatum, Bryum capillare, 
Encalypta streptocarpa, Fissidens adiantoides (a ground form) and 
Metzgeria furcata. In the ash-woods of the Carboniferous limestone, 
saxieolous species such as Neckera crispa, Orthotrichum anomalum var. 
saxatile, Trichostomum nitidum, Ditrichum flexicaule, Grimmia 
apocarpa, Barbula rubella, Madotheca platyphylla and Frullania 
Tamarisci, in addition to the above species, are common. 
(4) . The following species are characteristic of the oak-woods:— 
Catharinea undulata (sub-dominant), Tetraphis pellucida, Polytrichum 
aloules, P. piliferum (sub-dominant when conifers are abundant), P. 
juniperinum, Dicranum majus, Orthotrichum Lyellii, Weber a albicans, 
Mnium cuspidatum, M.hornum (sub-dominant), Campylopuspyriformis, 
C.fragilis, Leucobryum glaucum, Aulacomnium androgynurn, Plagio- 
' The Census Catalogue of British Mosses. York, 1907. 
Lett’s Catalogue of British Hepatics. Eastbourne, 1904. 
