ALLIED TO TORTULA FALLAX. 327 
pearance of being ex current ; the peristome is too short to show any 
trace of twisting, hut its structure is exactly that of T. fallax and 
T.-viumlis. 
I 
T. lurida (Dldpiiodon), Hornschuch, is another species, which is 
very well distinguished from any of the preceding by its patent, 
shorter or wider leaves, excepting in the length of its peristome, which 
does not differ in structure. It agrees so closely with them that it must 
he considered a member of the same family. 
The second section, containing those species which have an erect 
base to their leaves, includes : 
T. rig'idula (Dhh/modon) , Hedw. Muse. Frond, iii. p. 8, t. 4, which 
lie describes as " erecta, folds lanceolatis, e vasorum fasciculo cuspi- 
datis, rigidulis, operculo subulato curvulo ;" and in his ' Historia 
Analytical he continues, " Folia lanceolata, carinata, margine srepe re- 
flexo, fasciculo ductulorum valido, unico cuspidem extremain consti- 
tuente." His figure represents the leaf of a lanceolate outline with an 
erect base, from whence the upper portion is patent. 
This is Didijmodon rigid ulus of Hooker and Taylor, Muscol. Brit. 
t. 20, and of 'English Flora,' vol. v. p. 29 ; and it is Trichostomnm 
ngidulum, /3. densum, Bryol. Europ. Trichostomum, t. 7, and belli mp. 
Synops. p. 149, also of Wilson, Bryol. Brit. p. 114. Its habitat appears 
to be usually on walls ; it is probably generally distributed in Britain ; 
my specimens are from Scotland, Yorkshire, Sussex, and Cornwall. 
In the ' Bryologia Europava ' this Moss has scarcely been represented, 
the plate, in which it is delineated of the natural size, being occupied 
by the species here described as T. spadicea, but from this it is easily 
distinguished by its stiffer foliage, which is not oppressed and imbri- 
cated when dry, but " bristly," as stated in Eng. Flora, the leaves 
being slightly curved and loosely contorted, the erect base has many 
oblong, pellucid cells, and the stout nerve is continued with the lamina 
of the leaf into a thick, obscure point, which does, at first sight, appear 
as if the nerve was excurrent, as stated by Hedwig. 
It is not very obvious on what principle this species, which in the 
length of its peristome exceeds in development T. spadicea, should have 
oeen reduced to the subordinate position of a variety of that Moss 
T. shmosa (Dicranella, Wfls. mss.) has its long lanceolate lmeal or 
subulate leaves patent from a very short pellucid base, m winch the 
cells are all oblong and rectangular, and the margin erect, the upper 
