16 SYNOPSIS OF BEITISH MOSSES. 



Fmn. 4. Orthotrichse. 



Csespitose or pulvinulate, branches dichotomous and 

 fastigiate. L. apical cells punctulate, densely chloro- 

 phyllose, basal lax, narrow, hyaline. Calyptra large, 

 mitriform, plicate, often hairy, rarely inflated. Caps,, 

 immersed or exserted, symmetric, generally striate. 

 Perist. single or double, rarely albsent; ext. t. 16, 

 approaching in pairs; int. 8 or 16 cilia, or a torn 

 membrane. 



46. TJlota, Mohr. L. flexuose, much crisped when 

 dry, except U. MutchinscB, narrowly areolate at base. 

 Calyptra deeply plicate, rough, with yellowish hairs, 

 deeply incised at base. Caps, striate, sulcata when 

 dry, oval, exserted. 



46. Orthotriohum, Hedw. Pulvinate, rarely csespitose, 

 erect. L. ovate or elongate-lanceolate, minutely pa- 

 pillose above, rarely smooth, basal cells hexagono- 

 rectangular, hyaline. Calyptra campanulate-mitriform, 

 incised at base, less plicate than the last, pilose or 

 naked. Caps, rarely exserted, immersed, 8 — 1 6,' striate 

 and sulcate when dry, or rarely smooth. 



Tribe xiii. Schistostegace^. 



PI. annual, growing from a persistent confervoid 

 prothallus. Sterile pi. frondiform, 1. vertically in- 

 serted, confluent at base, fertile pi. frondose or leafless 

 below, and with a few horizontal small leaves above. 

 Cells lax. Caps, small, erect, subglobose, without 

 perist., lid convex, columella thick. Calyptra small 

 mitriform, or dimidiate. 



47. Schistostega, Mohr. The only genus. As 

 above. 



