118 APLOPERISTOMI. \_Didymodon. 



Bryum lineare. Dicks. Crypt. Fasc. 3. p. 6. t. 8. /. 2. 

 Bryum rigidulum. Dicks. Crypt. Fasc. 4. p. 12. 

 HAB. Walls and rocks. Not uncommon in Ireland. 

 " Habitus omnino Tortulse," Mr. Turner has well observed of 

 this plant ; indeed, so nearly does it approach to T. fallax, that 

 it will require an experienced eye to distinguish it without 

 having recourse to the peristome. The nerve of the leaf, how- 

 ever, is different, singularly rigid, of a brown colour, (as well 

 as the leaves themselves,) and decidedly running out beyond 

 the point of the leaf; thus the stems have a bristly appearance 

 from the stiffness and sharpness of the foliage. Hedwig's 

 figure, we must observe, does not give a correct idea of this 

 plant, which is, in reality, more different from D. trifarium 

 than his representation would lead us to suppose. We do not 

 think, indeed, that any stress can be laid upon the operculum, 

 which varies somewhat in length in each species ; nor can we 

 consent to their being placed in different genera in consequence 

 of the situation of the supposed male flowers. Schwaegrichen 

 has incorrectly quoted the Bryum lineare, Dicks, under Tri- 

 chostomum patens. 



8, D. trifarium ; leaves rather distant somewhat trifarious lanceo- 

 late rather obtuse carinated with the nerve scarcely reaching 

 to the point, capsule oblongo-ovate erect, lid rostrate. (TAB. 

 XX.) 



Didymodon trifarium. Swartz, Muse. Suec. p. 28. Hook. Fl. Scot. 

 P. II. p. 136. Brid. Meth. p. 102. Hobson, Brit. Mosses, v. 2. n. 

 4-1. Drummond, Muse. Scot. v. 2. n. 48. Arn. Disp. Muse. p. 35. 

 Swartzia trifaria. Hedw. St. Cr. v. 2. t. 28. 



Cynontodium trifarium. Hediv. Sp. Muse. p. 57. Schwaegr. Suppl. 

 v. 1. p. 114. 



Trichostomum trifarium. Smith, Fl. Brit. p. 1235. Engl Bot. t. 1707. 

 Trichostomum linoides. Smith, FL Brit. p. 1247.? Engl Bot. t. 

 2295. (not of Dicks.) 



Barbuln linoides. Brid. Meth. p. 90. Dill Muse. t. 47. / 39. 

 (according to the Rev. Mr. Oglander.) 



Trichostomum tophaccum. Funck, Deutschl. Moose, t. 17. n. 6. 

 HAB. On moist banks. 



Although very closely allied to the preceding species, this 

 may be known by the shorter, more patent, far less rigid, more 

 distantly placed, and somewhat trifarious leaves. In size it 

 varies considerably, and is often much branched with innova- 



