BARNES — NORTH AMERICAN MOSSES. 183 



b. Costa per current or excurrent, leaves not undulate. 



[D. Bonjeani may be sought here.] 



Guides in two rows D. majus, 74. 



Guides in one row. 

 Margin serrulate to middle of leaf, back of costa lamellose. 



Seta yellow, capsule long and narrow (1 : 5-6) D. consobrinum, 84- 



Seta red, capsule broader (1 : 4) . . D. scoparium, 73.i 



Margin entire to near apex, back of costa not lamellose. 



Cells above narrow (1 : 5-6) leaves brittle . . D. neglectum, 73. 



Cells above isodiametric, leaves not brittle D. brachycaulon, 88. 



2. Leaf cells not pitted or faintly so. 



Leaves quite entire or denticulate, subulate. 



Points very brittle, mostly broken . . . D. fragilifolium, 73. 



Points not broken 1>. elongatum, 71. 



Leaves entire, upper obtuse. 



Cells throughout elongated, thickened, pitted D. Groenlandicum, 89. 

 Cells short, quadrate above, not pitted . . D. Miquelonense, 72. 

 Leaves serrulate. 



Upper cells very irregular. 



Capsules cylindrical, striped or striated. 

 Costa at point of greatest leaf -width one-sixth or 



more !>• Muhlenbeckii, 72.3 



Costa at point of greatest leaf-width one-tenth or less. 

 Cells of upper third of lamina short (8-10 X 



10-17/0 D. pallidum, 76. 



Cells of upper third of lamina narrower, larger, 



(15 X 50//) D- rhabdocarpum, 73. 



Capsules ovate-oblong, not striped or but faintly D. congestum, 72. * 

 Upper cells regular, capsule obovate-oblong, striped D. fuscescens, 72. 



B. Capsule erect, symmetric. 

 Costa without stereids D- strictum, 69. 



iSee Appendix, nos. 77-83. 



* See Appendix, no. 74. 



s D. fuscescens L. & J. Man. 72 in part. 



* D. fuscescens longirostre and ayigustifoliumlLi. & J. Man. 72. See Appendix, nos. 



70, 71. 



