382 Wilson's notes on British muscology. 



31. F. Hihernica. — No good specimens of this Moss exist 

 in the Hookerian herbarium, and it is most probably not dis- 

 tinct from F. hygrometrica, which, in realit\', (as was first 

 pointed out to me by Mr John Nowel,) has the lower leaves 

 of the stem plane and minutely serrated. 



32. Polytrichum The " membrane" which connects the 



teeth of the peristome is an hemispherical expansion of the 

 columella, to which in most species it permanently adheres. 

 It is in fact a modification of the opercular membrane, or 

 metnla. The propriety of the latter name is clearly exempli- 

 fied in this genus, because the metula in this case does not 

 rise higher than the apices of the teeth of the peristome. The 

 substance which fills the operculum is, as Mr Valentine has 

 justly pointed out, an expansion of a portion of the thecal 

 membrane. The teeth of the peristome consist of two 

 lamina?, of which the innermost (as in every case where an inner 

 peristome exists at all) is connected with the sporular sac. 



33. P. aloides and P. nmmm These two Mosses have 



generally been considered scarcely distinguishable. It would 

 appear, however, that they are truly distinct species. The 

 first of these has a 4-winged columella; the other a cylin- 

 drical one, with large seeds. P. nanum^ therefore, ought 

 to be removed from the very doubtful genus Pogonatum of 

 Bridel. 



34. Brywn squarrosum No second locality in Britain for 



this Moss has yet been found; and there is reason to appre- 

 hend that the Moss no longer grows upon Knutsford moor ; 

 the ground having been drained and levelled. 



35. B. Tozeri. — This rare species has been found on 

 the banks of the Lee, near Cork, by Mr W. T. Alexander, 

 and near Penzance, by Mr Ralfs. 



36. B. annotinum, Hedwig. — Certainly distinct from B- 

 turbinatum, with a much closer affinity to B. nutans. In a 

 stone quarry, two miles north of Warrington, this usually 

 barren Moss produces fruit in considerable plenty, and the 

 barren gemmiferous shoots are there comparatively unfre- 

 quent. Tlie capsule has a pale waxy hue. 



