Analytic Keys to the Species of Mosses. 
31 
II. Cells of the exothecium prosenchymatous; seta often yellow; costa nar¬ 
row and well defined below. 
A. Seta red. 
Leaves, from a sheathing base, squarrose . . . . D. crispa, 1. 
Leaves not sheathing nor squarrose. 
Mostly erect, capsule cernuous.D. subulata, 9. 
Secund, capsule erect.D. curvata, 11. 
B. Seta yelloivish. 
Capsule symmetric, erect 
Capsule cernuous. 
Strumose . 
Not strumose . 
DICRANUM, p. 67. 
In this genus the structure of the costa is of diagnostic value. It is either 
composed of similar cells ( homogeneous), or composed of large parenchyma 
cells and small sclerenchyma cells ( stereides ). The large parenchyma 
cells (“ Deuter ” of Lorentz 1 2 : here translated guides) form a row (seldom 
double) in the middle of the costa, touching each other tangentially. They 
are comparatively large, but little thickened and either empty or starch¬ 
bearing. 3 
I. Monoicous, stems radieulose only at base; costa long excurrent , homo¬ 
geneous. 
Capsule erect, not strumose. 
Striate and furrowed when dry . . . D. hyperboreuin Mull. 4 
Neither striate nor furrowed when dry . . . D. fulyellum, 1. 
Capsule cernuous, strumose. 
Leaf cells not papillose, capsule oblong-cylindric . D. Starkei, 2. 
Leaf cells with papillae over the partitions, capsules short ovate. 
Leaves falcate-secund.D. falcatum, 3. 
Leaves spreading.D. Blyttii, 4„ 
1 Renauld & Cardot: Bot. Gaz., xiii (1888) 197. pi. XIII. 
2 Pringsh. Jahrb. f. wiss. Bot., vi. 374. 
3 Cf. Limpricht: Die Laubmoose, p. 23. 
4 Barnes: MSS.; var. papillosum, Renauld & Cardot: Bot. Gaz. x iv. (1889). 91. 
D. Fitzgeraldi. 3 
B. cerviculata, 5. 
D. lieteromalla, iO. 
