F0TTIEI. 269 



medial line, entire or pierced. — Hook, fy Wils. t. xiv. ; Eng. 

 Bot. t. 1408. ; (Plate 23, fig. 1) ; Moug. 8f Nest. n. 310. 



On walls, etc., in calcareous districts. Bearing fruit in 

 March. 



Forming patches of various sizes. Stems from 1 line to £ 

 an inch long ; teeth very variable. 



4. A. latifolia, Nees 8f Hornsch.; gregarious, bulbiform, 

 very short; leaves imbricated, -widely obovate or roundish, 

 apiculate or obtuse, glossy, concave ; nerve ceasing below the 

 tip ; sporangium oval or oblongo-elliptic ; lid shortly rostrate ; 

 teeth lanceolate, entire or cloven, united at the base by a nar- 

 row membrane. — Hook. 8f Wils. t. xxxiii. ; Eng. Bot. t. 2535. ; 

 Grev. Sc. Crypt. II. t. 149. ; {Moug. Sf Nest. n. 1105.) 



Scotland. Rare. Bearing fruit in spring. 



Monoicous. Leaves imbricated so as to form a little hop- 

 like bulb, whitish, shining ; leaf-cells large. 



88. POTTIA, Ehrh. 



Sporangium exserted or immersed ; veil cucullate ; peri- 

 stome none ; apex of columella falling away with the lid ; leaf- 

 cells quadrate or rectangular, enlarged below. 



1. P. cavifolia, Ehrh. ; stem very short ; leaves spreading, 

 ovate or oblongo-lanceolate, mucronate or piliferous from the 

 excurrent nerve ; fruitstalk short ; sporangium oval ; lid 

 obliquely rostrate, shorter than the sporangium. — Hook. §• 

 Wils. t. vii. ; Eng. Bot. t. 1889. ; (Moug. $ Nest. n. 308.) 



On clay walls, the naked ground, etc. Common. Bearing 

 fruit in winter. 



Gregarious or csespitose, monoicous. Leaves concave ; nerve 

 bearing three or four membranous appendages on the upper 

 side, which at first consist of a swollen follicle on either side 

 of the nerve. (Plate 23, fig. 2, e.) 



