206 DIPLOPERISTOMI. [Bryum. 



abundant, often of a deep brown or reddish colour, in which 

 the foliage partakes to a degree. The leaves are more or less 

 crowded, generally erecto -patent, the nerve reddish, the margins 

 revolute, the base decurrent, almost as much so as in Mnium 

 Duvalii of Schwaegr. SuppL t. 79. which, perhaps, may be only 

 a variety of our plant. 



It must be allowed that the differences between this moss 

 and B. c&spiticium are almost insufficient, and that it is more 

 distinguishable by its larger size, proliferous habit, and brown 

 or purple hue, than by any more essential characters ; all of 

 which may be fairly attributable to the place of growth, whilst 

 the other affects dry banks and walls ; and we should willingly 

 have reduced these species to varieties, if the example of all 

 preceding Muscologists had not forbidden it ; not one of them 

 having expressed the least doubt as to the identity. 



We wish also that we could discover characters that would 

 better indicate a specific distinction between this species and the 

 preceding B. alpinum ; which, always growing upon exposed 

 rocks, has a dense habit and is never proliferous. The place of 

 growth may account also for the more erect, rigid foliage ; but 

 this is certainly narrower than in our present plant, and the 

 capsule is usually shorter. 



20. B. demissum ; stems very short branched, leaves ovate cuspi- 

 date-acuminate reticulated, their nerve excurrent, fruitstalk 

 arched, capsule curved and pyriform pendulous, the mouth 

 oblique. (SUPPL. TAB. VI.) 



Bryum demissum. Hook. Muse. Exot. v. 2. t. 99. Grevitte, Scot, 

 Crypt. Fl. v. 2. t. 92. Am. Disp. Muse. p. 46. 

 Bryum curvulum. Schleicher. Cat. 



Meesia demissa. Hoppe et Hornsch. MSS. Funck, Deutschl. Moose, 

 t. 28. n. 4. 



Timmia. Nov. Sp. Schmidt, MSS. 



HAB. Rocks upon Craigcalliach and several other of the 

 Breadalbane mountains, always in very elevated and 

 very exposed situations. 



This curious and very distinct moss, although inhabiting 

 several distant parts of Europe, yet seems to be of very local 

 occurrence. We know that it is found in Switzerland, in Sa- 

 voy, in Salzburg, in Norway, and in Britain ; every where in 



