170 TORTULACE^E. 



dry, lower short, oblong-spathulate, upper longer, oblong, shortly 

 and slightly acute ; margin plane, slightly irregular towards apex 

 with the projecting transverse cell walls, but not papillose ; nerve 

 excurrent in a short point ; upper cells rather large, hexagonal, 

 thin-walled, smooth. Seta short, slender ; capsule shortly oval 

 or turbinate, when empty truncate, wide-mouthed and almost 

 hemispherical, thin-walled, pale brown, exannulate ; lid flat, with 

 a very oblique, more or less longly rostrate beak. Calyptra 

 smooth. Peristome none. Spores large, minutely punctulate. 

 Autoicous. 



Hab. Banks, fallow fields, etc. ; very common. .Fr. winter. 



The commonest species of the genus, and recognised without difficulty by the leaf 

 form and the short truncate capsules with obliquely rostrate lid. The capsule is, 

 however, somewhat variable in length and form. 



* Pottia intermedia Fiirnr. (Gymnostomum intermedium 



Turn. ; P. lanceolata var. gymnostoma Schp., Syn.) 



(Tab. XXVI. A.). 



Taller, rather larger in all its parts ; leaves longer, margin 

 revolute at middle, at apex slightly rough with projecting 

 papillae as well as with the transverse cell walls ; areolation 

 slightly papillose at back in the upper part of the leaf. Capsule 

 longer, oblong, more or less elongated ; peristome absent or very 

 rudimentary. Annulus broad. 



Hab. Walls, fallow fields, etc. ; frequent. Fr. winter. 



In its typical form a markedly different plant from P. truncatula, but the above 

 characters are not always pronounced, and the revolute margins and papillose leaves 

 are sometimes correlated with a very short, truncate capsule. The papillosity of the 

 leaves does not, indeed, seem to afford a very stable specific character in this genus. 



It frequently grows with P. lanceolata, but I have never found any trouble in 

 separating the two ; apart from the peristome the latter has narrower, more 

 regularly cylindrical, dark red or purplish capsules, thick-walled, narrower at the 

 mouth, with a regularly conical lid, obtuse, and of variable length ; the present plant 

 has the ripe capsules always paler, brown, broader, more or less wide-mouthed, with 

 the lid as in P. truncatula wide and fiat at the base, with a narrow and oblique 

 rostellate beak. In addition to this, the spores in P. intermedia are much larger, 

 being double the diameter of those of P. lanceolata, and the areolation also, as Braith- 

 waite points out, is larger than in that species. It is difficult therefore to see why 

 Schimper unites the present plant with P. lanceolata rather than with P. truncatula. 

 I have not seen any specimens that would bear out the supposition, but it is difficult 

 to resist the conclusion that there are probably two plants confused under this name, 

 the more so as Boulay, who follows Schimper on this point, and whose care and 

 accuracy of observation are noticeable throughout his work, distinctly attributes to it 

 almost all the characters I have above enumerated as distinguishing P. lanceolata. 



I am unable to see anything in P. littoralis Mitt, but a form of P. intermedia 

 somewhat intermediate between that and P. truncatula, which latter it resembles in 

 the smooth, slightly smaller, not papillose cells, with the cell walls somewhat more 



