SO TORTULA. 



12. TORTULA. 



GEN. CHAR. Fruitstalks terminal; Peristome single, of 

 32 filiform, twisted teeth, more or less united at the 

 base by a tubiform membrane; Calyptra dimidiate. 

 (TAB. II.) 



Not only in the Syntrichice of Bridel and Mohr, but in several 

 other species of the present genus, the membrane uniting the 

 teeth at the base is sufficiently visible, as well in T. cuneifolia 

 as in T. muralis, T. lorluosa, and T. unguiculata ; so that we 

 cannot avoid re-uniting the Syntrichice with the older genus Tor- 

 tula. 



T. rigida ; stems scarcely any ; leaves patent, oblong, rigid, 

 their margins much indexed, nerve broad ; capsule oblong, 

 lid conical, acuminate. (TAB. XII.) 



T. rigida. Swartz Muse. Suec. Turn. Musc.Hib. p. 43. Engl Bot. 

 1. 180. Barbula rigida. Hcdw. St. Cr. v.l.t. 25. Dill. Muse. t. 48./. 47. 



HAB. Clay banks. 



This species differs from all its congeners in the rigidity 

 of its leaves, their broad nerve and very involute margins, as 

 well as in the peristome, of which the laciniae are short, di- 

 stant, and slightly twisted. It is remarkable that botanists 

 in general, and Mohr especially, who is so attentive to the 

 structure of the leaves of mosses, have omitted to notice the 

 nerve, which is very broad and very apparent when the mar- 

 gins of the leaf are unrolled by art. Some specimens which 

 we have received from Sweden have the leaves so broadly 

 ovate and obtuse as to be nearly rotundate, yet we do not 

 think that they can be more than varieties. 

 T. muralis ; stems short ; leaves patent, lineari-oblong, their 

 margins recurved, nerve produced beyond the leaf into a 

 'white hair-like point; capsule oblong; lid conical, acumi- 

 nate. (TAB. XII.) 



T. muralis. Hedw. Sp. Muse. Swartz Muse. Suec. Turn. Muse. 

 Hib. p. 50. Engl. Bot. t. 2033. Barbula muralis. Mohr. Moug. et 

 Nestl n. 127. T. aestiva. Brid.Dill. Muse. t. 45. f. 1*. 



HAB. On walls and stones. 



This and T. muralis are the only British species whose 

 nerves terminate in diaphanous hair-like points. The T 



