THE POLYTRICHACEZ OF WESTERN NORTH AMERICA 295 
indistinct; Peristome present; teeth 32 (in the included species), in 
P. alpinum doubled so one might count 64. Lid hemispheric, more 
or less long-beaked. Pedicels single, rarely several at one tip, more 
or less elongated, purple. 
Number of species in western North America, 4; total number spe- 
cles, about 133. 
THE WEST NORTH AMERICAN SPECIES,——A COMPARISON AND KEY. 
1. Leaves very much crisped when dry. 
2. Marginal cells of lamelle smooth, not thickened. 
ae Reetha or 
4. Capsule without stomates. 
5. Capsule papillose. 
6. Marginal cells of lamellee differing little in size and form 
ftom the OtMenSeei saa be. 1. P. contortum. 
1. Leaves hardly or not at all crisped when dry. 
2. Marginal cells of lamelle papillose or rough, thickened. 
3. Teeth 64, or 32 double ones. 
4. Capsule with stomates. 
5. Capsule not papillose. 
6. Marginal cells of lamella ovate, width to length as 1: 
372, .abeer than the others. 2) 5. 4. P.alpinum. 
ae) Lecth23. 
4. Capsule without stomates. 
5. Capsule papillose. 
6. Marginal cells of lamelle oval or flat-topped, width to 
length as 14--2:1, larger than the others. 
2... Capilare: 
6. Marginal cells of lamellze round, about the same size as 
PH rObD ens Wey mie ery tiie enV ee Be PS UNA Cer ume. 
1, Pogonatum contortum (Menz.) Lesq., in Mem. Calif. Acad. 1, 
D. 27. 
Pogonatum erythrodontium Kindb., in Mac. Cat. p. 150 (1892). 
Pogonatum atrovirens Mitt.,4 in Journ. Linn. Soc. 1864, p. 49. 
** An examination of P. atrovirens Mitt. shows it to be P. contortum. Type material 
from the Mitten Herbarium, now owned by the New York Botanical Garden, and also 
material collected by Macoun at Hastings, Burrard Inlet, near Vancouver, British 
Columbia, was compared with authentic P. contortum. The capsules are papillose 
asin P.contortum. The basilar areolation is the same in leaves taken from correspond- 
ing parts of the stem. The leaves in both vary in the size of the sheath, those near 
the base of the stem having larger sheaths than those near the tip. Since these con- 
stitute the characteristics upon which P. atrovirens Mitt. is founded, it reduces to 
P. contortum. : 
