ISOTHECII. 147 



sporangium elliptic-oblong; lid conical, apiculate. Hook, fy 

 mis. t. liv. 



At the roots of trees near water. Yorkshire and Lancashire. 

 Bearing fruit in early summer. 



Monoicous ; forming little, soft, deep-green cushions. Stems 

 densely crowded ; leaves spreading, with a short simple or 

 forked nerve ; cells large, angular, with a distinct primordial 

 utricle ; fruitstalk inch high ; sporangium oval-oblong, ta- 

 pering below ; lid conical, soon falling off; inner peristome 

 reddish-brown. 



Differs from Leskta in the reticulation and the nature of the 

 inner peristome. 



23. PTERIGYNANDRUM, Hedw. 



Sporangium symmetrical ; peristome double ; outer of six- 

 teen short teeth; inner an irregular very short membrane, with 

 sixteen short processes more or less adherent to the outer 

 teeth ; rhizoma creeping ; branches and branchlets secund ; 

 leaf-cells rhomboid, except at the angles, where they are 

 quadrate. 



1. P. filiforme, Hedw. ; branches of secondary stem fili- 

 form, incurved, fasciculate ; leaves subsecund, ovate, acumi- 

 nate, two-nerved or with a single nerve reaching halfway; 

 sporangium elliptic, oblong; lid rostrate. Hook. Wils. t. xiv.; 

 Eng. Bot. t. 2297 in part, 2526. ; (Moug. % Nest. n. 210.) 



On rocks and trunks of trees, especially beech, in moun- 

 tainous districts. Bearing fruit, but rarely, in spring. 



Dioicous ; forming broad, green tufts. Branches and 

 branchlets arcuate, leaning one way, more or less attenuated, 

 somewhat fasciculate; leaves crowded, sometimes spreading, 

 often secund, imbricated when dry, papillose, ovate, slightly 

 attenuated, serrate above with a single nerve reaching halfway, 



L 2 



