MOSSES WITH A HAND-LENS XI 



. PAGE 



Terrestrial (or a few aquatic), seldom slender or 



floating, with capsules exserted on long setae..2i; x 



21. Tree growing species with the capsules partially 



immersed in the perichaetial leaves or at 



most barely exserted 23. 



Not growing on trees, or if so with capsules 

 long exserted 22. 



22. Leaves subopaque, dense, usually small; leaf- 



cells short Leskcaccae. 108 



Leaves nearly transparent, leaf-cells in most 

 cases elongated ; peristome with cilia except 

 in species with erect capsules Hypnaccae. 114 



23. Stems and branches flattened ; leaves appear- 



ing two-ranked Neckcraceae. 143 



Stems and branches nearly terete; leaves not 



appearing two-ranked Lcucodon. 141 



KEY TO GENERA, 



Plants with luminous protonema, growing ex- 

 clusively in caves and dark holes. .Schistostega. 86 



Plants gray to gray-green, growing in bogs and 



swamps Sphagnum. 1 1 



Plants not gray (except Leucobryum) growing 

 in various situations i. 



1. Acrocarpous A. 



2. Pleurocarpous B. 



A. 



1. Capsules square in cross-section; calyptra dense- 



ly hairy Polytrichum. 19 



Capsules round in cross section ; calyptra ex- 

 tinguisher-like, completely covering the cap- 

 sule Encalypta. 76 



Capsules round in cross-section; calyptra various. 2. 



2. Blackish to brownish-green ; growing on the 



bark of living trees 3. 



Blackish to brownish-green, growing on rocks .-..34. 

 Green, growing in various situations but not on 



trees 5. 



