BllYEI. 205 



58. ORTHODONTIUM, Schwceg. 



Sporangium symmetrical; spore-sac small; peristome 

 double ; external of sixteen rather distant teeth, inner a mem- 

 brane divided almost to the base into sixteen processes, with- 

 out intermediate cilia. Delicate, perennial, tufted Mosses, with 

 very narrow leaves. 



1 . O. gracile, Schwceg. ; monoicous ; leaves crowded, spread- 

 ing, linear, setaceous, very obscurely toothed above ; nerve 

 reaching almost to the apex ; sporangium inclined, elongated, 

 clavate, with a long tapering apophysis ; lid with a short beak. 

 —Hook. # Wils. t. xlvii. ; Eng. Bot. t. 2835.; (Plate 18, 

 fig. 4.) 



On sandstone rocks. Cheshire and Yorkshire. 



Forming somewhat pulvinate, bright-green tufts. Leaves 

 more or less waved; leaf-cells rather large; antheridia in the 

 axils of the leaves ; spore-sac separated from the walls of the 

 sporangium ; ring obsolete ; peristome inserted deeply within 

 the mouth ; the outer teeth much more irregular than in 

 Bryum, and not seen at all when the sporangium is dry; 

 spores rather large, yellowish. 



59. AULACOMNION, Schwaeg. 



Sporangium furrowed when dry; peristome almost as in 

 Bryum ; spores very small. Perennial Mosses, growing in 

 marshes or dry ground, and bearing terminal globular masses 

 of gems. 



1. A. androgymim, Schwceg. ; dioicous; leaves lineari -lan- 

 ceolate, irregularly toothed at the apex ; leaf-cells papillose on 

 either surface; sporangium oblong, regular, slightly cernuous; 

 male flowers gemmiform. — Hook. §■ Wils. t. xxviii. ; Eng. Bot. 

 t. 1238. ; {Moug. if Nest. n. 620.) 



