BARNES — NORTH AMERICAN MOSSES. 183 



b. Costa pereurrent or excurrent, leaves not undulate. 



[D. Sonjeani may be sought here.] 



Guides in two rows ]). 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. consobrinnm, 84. 

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

 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. brachycanlon, 88. 



2. Leaf cells not pitted or faintly so. 



Leaves quite entire or denticulate, subulate. 

 Points very brittle, mostly broken . . . D. fragilifoliam, 7.3. 



Points not broken D. elongatum, 71. 



Leaves entire, upper obtuse. 



Cells throughout elongated, thickened, pitted D. Oroenlandicnm, «9. 

 Cells short, quadrate above, not pitted . . D. Miqnelonense, 7f . 

 Leaves serrulate. 



Upper cells very irregular. 

 Capsules cylindrical, striped or striated. 

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



more D. MnMenbeckii, 72.= 



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

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



lO-llM) D. pallidum, 76. 



Cells of upper third of lamina narrower, larger, 



(15 X 50m) D. rhabdocarpum, 73. 



Capsules ovate-oblong, not striped or but faintly D. cong'estnm, 72.' 

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



B. Capsule erect, symmetric. 

 Costa without stereids ...... D. strictum, 69. 



1 See Appendix, nos. 77-83. 

 ° See Appendix, no. 74. 

 ' £>. fuscescens L. & J. Man. 72 in part. 



* J}, fuscescens longirostre and angicstifoliwmZ'Li. & J.Man. 72. See Appendix, nos. 

 70, 71. 



