378 Mr. R. Spruce on the Musci and Hepatica of the Pyrenees. 



240. T. vinealis, Brid. Br. Univ. 1. p. 830 (sub Barbula) ; Br. 

 Europ. /. c. p. 24. t. 10. 



Var. ^. flaccida, Br. Europ. ; M. P. l^A^.—Hab. Zj P. c. ad 

 ripas rivuli qui ad monasterium Medous prope B. -de-Biff orre ori- 

 ginem suam habet. 



Var. nivalis, M. P. J 85. — Hab. Z4 in rupibus frigidis ab aqua 

 nivali irrigatis vallis alpinse Esquierry dictse. 



This second variety forms- large compact tufts on the ledges of 

 dripping rocks, growing near Senecio Tournefortii, Euphrasia minima 

 and Luzula spadicea. The stems attain a length of 6 or 8 inches, and 

 are clad throughout with leaves of a deep reddish brown. Hence its 

 aspect is very different from that of the ordinary form of T, vinealis, 

 but without the fruit I do not venture to separate it. 



41. Didymodon, Schwgr. (ex parte), 



241. D. rubellus, Hoffm. Deut. PL 2. p. 33 (sub Bryo) ; Br. 

 Europ. Didymodon, p. 3. t. 1 ; M. P. 186. Weisia curvirostra, 

 H. et T. ! Muse. Brit. p. 84. t. 14. 



Hab. Zo_2 in muris, rupibus, &c. 



242. D. cylindricus, Bruch in Brid. Br. Univ. 1. p. 806 (sub 

 Weisia) ; Br. Europ. /. c. p. 5. t. 3 ; M. P. 187. 



Hab. Z2 P. occ. in saxis rivulorum supra thermas diet, les Eaux 

 Bonnes 'y P. e. in vieinia B.-de-Luchon, frequens, ioeis Superba- 

 ffnereSj Lac de Seculejo, Cascade du Cceur, &c. 



42. Trichostomum, Hedwig. 



Obs. T. flexicaule is the only species of this genus which seems 

 absolutely confined to calcareous rock : T. mutabile, crispulum and 

 tophaceum were observed on no other rock in the Pyrenees, but in 

 England I have occasionally seen them in habitats where no trace of 

 carbonate of lime was to be detected. The last five species form 

 part of the genus Leptotrichum of Hampe, and are placed by C. Muel- 

 ler in his tribe Leptotrichacece (Conf. Syn. Muse. p. 415). 



§ 1. Crispula. 



243. T. mutabile, Bruch mst. ; Br. Europ. Trichostomum, p. 8. 

 t. 5;M. P. 188. 



Hab. Zi locis calcareis. P. oec. ad pagum Narcastet. P. c. in 

 rupibus umbrosis prope B. -de-Biff orre {Chemin de Labassere et 

 Bains de Salut). An revera a sequente distincta species ? 



244. T. crispulum, Bruch et Muell. in Regensb. Bot. Zeitung, 

 1829; Br. Europ. I. c. t. 4; M. P. 189. Didymodon Benthamii, 

 Arnott ! in Edinb. New Philosoph. Journ. 1846. 



Hab. Zj in rupibus calcareis irroratis Pyren. occidentalium, 

 frequens. Pau ; Narcastet, &c. Restinclieres prope Montpellier 

 (Arnott!). 



