Didymodon.] A P L O PER I S T O M I. 117 



Engl. I$ot., to be but plants of Weissia striata ; and that the 

 figure in Engl. Bot. is given from foreign specimens. We are 

 still, therefore, of opinion that Mr. Drummond is the first and 

 only discoverer of this very rare plant. In Switzerland it is, 

 however, common upon the lofty mountains, and every where 

 remarkable for its glaucous green hue.* The peristome is long, 

 red, consisting of 32 filiform teeth, placed in pairs. 



6. D. Bruntoni ; stems elongated pulvinate branched, leaves lan- 



ceolato-subulate margins slightly recurved scarcely serrated 

 twisted when dry, capsule erect ovate, lid rostrate. (SUPPL. 

 TAB. IV.) 



Didymodon Bruntoni. Am. Disp. Muse. p. 36. 

 Dicranum Bruntoni. Engl Bot. t. 2509. 



Didymodon obscurum. Kaulfuss in Sturm. Deutschl. Fl. cum. ic. 

 Schwaegr. Suppl v. 2. p. 80. t. 125. Funck, Deutschl. Moose, t. 14. n. 

 1. Grev. Scot. Crypt. Fl. t. 193. 



Dicranum polycarpum. Hooker and Tayl. Muse. Brit. ed. 1. p. 57. 

 Hook. Fl. Scot. P. II. p. 133. Hobson, Brit. Mosses, v. 2. n. 36- 

 Drummond, Muse. Scot. v. 2. p. 37. 



HAB. Rocks in alpine districts, perhaps not uncommon. 



Pentland Hills, abundant. Dr. Greville. 

 Habit of Weissia crispula, and affecting similar situations; 

 but it is a much larger plant, with broader capsules, and less 

 glossy foliage. It is illustrated for the first time, and extremely 

 well, by Dr. Greville, in his admirable work, the /Scottish 

 Cryptogamic Flora. 



7. D. rigidulum ; leaves closely imbricated on all sides, lanceolate 



much acuminated carinated with the rigid nerve running be- 

 yond the point, capsule oblongo-ovate erect, lid rostrate. 

 (TAB. XX.) 



Didymodon rigidulum. Hedw. St. Cr. v. 3. t. 4. Hook. Fl. Scot. 

 P. II. p. 135. Schwaegr. Suppl v. 1. p. 116. Brid. Meth. p. 102- 

 Moug. et Nestl. t. 612. Am. Disp. Muse. p. 35. 



Trichostomum rigidulum. Smith, FL Brit. p. 1238. Engl. Bot. t. 

 2178. Turn. Muse. Hib. p. 34. 



Trichostomum lineare. Smith, FL Brit. p. 1240.? Engl. Bot. t. 

 1598. Brid. Meth. p. 84. 



* The stems of this plant are infested with a minute filamentous parasite, 

 bearing white powdery granules. This appearance must not be confounded 

 with the calcareous clothing to the stems of Weissia verticillata. 



H3 



