10 KEY TO THE FAMILIES OF MOSSES 



Leaves not papillose, (slightly so in species of Leptodon, Cryphea, 



and Bryhnia) 23 



23 — Basal joints of peristome teeth marked with very fine transverse 

 lines; segments of inner peristome well developed, keeled; cilia 

 present (inner peristome without cilia and with narrow segments in 

 many species with erect or suberect capsules. The transverse 

 lines, even, are lacking in most of the species of the Ciimaceae 

 and Entodonieae) ; leaf-cells elongated, sometimes rhomboidal but 

 never rounded in the main portion of the leaf (except Porotrichum) 



Hypnaceae 

 Basal joints of teeth without fine transverse lines; capsules sym- 

 metric, usually erect on straight setae; cilia of inner peristome 

 lacking; segments usually narrowly linear, occasionally the inner 

 peristome almost lacking. Practically all growing on the bark of 



living trees 24 



24 — Leaf cells elongated as in the Hypnaceae; peristome teeth often 



united in pairs. Rare, mostly minute mosses Fabroniaceae 



Leaf cells short and rounded; larger plants, many very common. . . .25 

 25 — Stems and branches flattened; leaves appearing two-ranked. Neckeraceae 

 Stems and branches nearly terete; leaves not appearing two-ranked. 



Leucodonlaceae 



