BARNES — NORTH AMERICAN MOSSES. 199 



§IV. Guembelia. 

 Lamina above 2-i-stratose. 

 Calyptra cucullate. 

 Leaves hair pointed. 



Basal cells quadrate G. tenerrima, 188. 



Basal cells rectangular .... Gr. commutata, 145. 



Leaves not hair-pointed, blunt or hyaline apiculate. 

 Teeth entire, annulus simple, indistinct . . G. snlcata, 186. 

 Teeth irregularly lacerate or bifid, annulus com- 

 pound, triple ...... G. unicolor, 146. 



Calyptra mitrate. 

 Leaf margins plane. 

 Hair point very rough, lid straight beaked G. lencophaea, 144. 



Hair point faintly denticulate, lid obliquely 



beaked G. sarcocalyx, 190. 



Leaf margins recurved. 

 "Walls of basal cells sinuate . . . G. Pennsylvanica, 144. 



Walls of basal cells smooth G. ovata, 143. 



Lamina having only the margin 3-4-3tratose. 

 Leaves muticous or hyaline, apiculate. 



Costa reaching the hyaline apex, dioicous . . G. ^longata, 185. 

 Costa vanishing far below apex, monoicous G. Coloradensis, 143. 



Leaves hair-pointed. 

 Annulus wanting. 

 Calyptra mitrate, covering whole capsule G. calyptrata, 144. 



Calyptra cucullate G. montana, 145. 



Annulus present. 



Cells of leaf base elongated (1 : 4 to 1 : 8) . G- Donniana, 142. 



Cells of leaf base short (1 : 2), borders plane G. alpestris, 146. 



Cells of leaf base short, borders recurved G. microtricha, 187. 



Lamina of a single layer of cells G. mollis, 189. 



The descriptions of OO. oincUdodontea C. Mull., orassinervis C. 

 Moll., tenella C. Mull., and Mannice C. Mull, are incomplete and as no 

 authentic material is at hand they are not included in the key. See Ap- 

 pendix, nos. 182, 183, 184, 184a. 



RHACOMITRIUM, p. 147. 



I. Branches fastigiate. 



Leaves with a short hyaline point ... R. Sudeticnm, 149. 



Leaves muticous. 



Costa with 2-4 lamellae at back .... R. patens, 147. 



