Tortula.] MUSCI. 25 



18. Tortula, Hedw. 



Seta terminal. Peristome single of 32 teeth spirally twisted 

 above, united more or less below into a tubular membrane. 

 Calyptra dimidiate. 



1. T. rigida, Turner. Stems very short; leaves few linear 

 more or less broad, incurved, their nerve more or less broad, 

 concave, rigid ; their margins involute ; capsule oblong ; lid ros- 

 trate. Turner Muse. Rib. p. 43. Muse. Brit. ed. 2, p. 53, 

 t. 12. 



On walls and ditches ; very common. This is so variable in the 

 breadth of the leaves, the breadth of their nerves which are sometimes 

 concealed by the involute edges of the leaves, and by the length of the 

 rostrum of the lids that I find the greatest difficulty in comprehending 

 the T. enervis and T. brevirostris of authors. The former from 

 Stiblington, in Kent I find has a real nerve, the outer leaves to be 

 much shorter and wider than the inner, and the lid not to exceed in 

 some instances half the length of the capsule. Again, Funcke's spe- 

 cimens of T. brevirostris are furnished with lids at least as long, and 

 have the leaves of the shape of the outer of the Stiblington plant. 

 T. brevirostris of Musci Americani, as well as specimens sent to me 

 by Mr. Drummond under that name from North America, are properly 

 our Irish T. rigida. 



2. T. convoluta, Swartz. Stems short ; leaves oblongo-lan- 

 ceolate, acute, their margins plane ; those of the perichcetium 

 closely convolute; capsule oblong; lid rostrate. Swartz. Muse. 

 Suec. Muse. Brit. ed. 2, p. 54, t. 12. 



On ditches near Bantry, Miss Hulchins. Dunkerron, not uncom- 

 mon. The leaves are smaller than in the otherlrish Tortula. The 

 capsule is slightly curved at the top to one side. The leaves of 

 the past season are brownish ; of the present, of a lively green, which 

 also is the hue of the perichcetium ; upon examination we find this to 

 be truly lateral or radicular. The Tort, piljera of Hook. Muse. exot. 

 t. 12, is similarly circumstanced. 



3. T. revoluta, Bridel. Stem short ; leaves lanceolate acute, 

 their margins closely revolute, those of the perichcetial leaves 

 sheathing, involute ; capsule oblong ; lid shorter than the cap- 

 sule. Bridel in Schrad. Journal. 1800, v. 1, p. 299. Muse. 

 Brit. ed. % p. 54, t. 12. 



On ditches near Cork, Mr. James Drummond. Rare. 



4. T. muralis, Hedw. Stems short; leaves patent, narrow, 

 oblong, their margins recurved, their nerve excurrent into a 

 long diaphanous point ; capsule ovato-cylindraceous ; lid conical, 

 acuminate. Hedw. Sp. Muse. p. 123. Muse. Brit. ed. 2, p. 55, 

 t. 12. 



On walls and ditches ; very common. The nerve is incrassated 

 above ; the diaphanous point without any serrulations ; the teeth of 

 the peristome are not united till they reach downwards to the mouth of 

 the capsule. 



c 



