174 TORTULACE^E. 



capsule small, ovate, often slightly unequal, broad and rounded at 

 base, narrowed at the mouth with a rather long oblique lid ; 

 peristome teeth small, narrow, entire or slightly cleft, imperfect ; 

 spores minutely papillose, Autoicous. 



Hab. Chalky fields ; very rare. Sussex ; Kent. Fr. spring. 



Easily distinguished from P. Starkeana by the smooth calyptra and plane- 

 margined leaves ; from P. lanceolata by the yellow seta, plane margins, and smaller 

 capsules ; from the other lowland species by the presence of a peristome ; the leaves, 

 too, are unlike those of any of the other species. 



11. Pottia lanceolata CM. (Leersia lanceolata Hedw.) 

 (Tab. XXVI. H.). 



Bright green, in dense tufts, rather tall. Leaves variable, 

 from oblong-lanceolate to obovate, acute, nerve rather broad in 

 the upper part of the leaf, excurrent in a longer or shorter point, 

 margin revolute, cells in the upper part moderately large, 

 incrassate, densely papillose or almost smooth at back. Seta 

 yellow when young, orange red when ripe ; capsule narrowly 

 elliptical, dark reddish brown, thick-walled, narrowed at the 

 mouth; calyptra smooth, lid rather long, oblique, or short and 

 conical ; peristome teeth long, narrow, of 8-10 articulations, 

 erecto-patent or spreading when ripe, reddish or pale, with a line 

 down the middle and usually slightly cleft at apex, sometimes 

 perforate along the median line ; spores finely granulated. 

 Autoicous. 



Hab. Dry banks, wall tops, etc. Frequent. Fr. spring. 



P. lanceolata is readily known by its highly developed peristome and narrow, 

 elongate, dark purplish capsules. The peristome teeth are sometimes pale, and 

 frequently become whitish after maturity. The nerve is slightly but distinctly 

 thickened towards the apex of the leaf, and not unfrequently produces granular out- 

 growths on its surface in that part. It is in some respects a variable plant, but the 

 variations as a rule are not such as to give rise to difficulty in identifying it, nor of 

 sufficient importance to be worth description. 



In the leaf P. lanceolata much resembles Tortula atrovirens, but that has a still 

 greater development of nerve, the leaves are narrower, the nerve only very shortly 

 excurrent, and the capsule more truncate and otherwise differing. 



12. Pottia latifolia CM. (Weisia latifolia Schwgr.) 

 (Tab. XXVI. J.). 



Plants very short, bulbiform, gregarious or clustered, shining, 

 pale green or whitish ; leaves imbricated , broadly obovate or 

 orbicular, very concave, thin, rounded at top or the upper ones 

 very slightly and obtusely apiculate, margin plane or incurved, 



