WILLIAMS: THE GENUS DESMATODON 219 
mm, up to 2 cm, high; stem leaves more or less erect or flexuous 
and twisted when dry, from oblong-linear to oblong-spatulate, up 
to 3.5 mm. long by I mm. wide, acute, the margins toward apex 
flat and mostly not quite entire, of a single layer of cells, farther 
down more or less revolute on one or both sides and usually of a 
double layer of two to four rows of slightly colored cells; costa 
smooth on the back, mostly excurrent into a short awn, in cross- 
section showing two guide-cells, a single row of about three cells 
nearly as large on the ventral side and on the dorsal side a stereid 
band with the outer cells differentiated; cells of upper part some- 
what rhomboidal to hexagonal, up to 20 u wide by 25 u long, rarely 
smooth or nearly so but mostly papillose on both sides; cells of 
lower part smooth, lax, pale, up to 30 « wide by 140 u long; perichae- 
tial leaves scarcely differentiated; seta erect, 1.5-2 cm. long, yel- 
low or finally reddish; capsule nodding to horizontal, somewhat 
curved-ovate, the mouth rather small and oblique, the few stomata 
in one row at the base; peristome reddish brown, densely papillose, 
the teeth mostly divided irregularly into two forks, one or both of 
which are more or less perforate or split in the lower part, the 
basilar membrane extending well above the rim; annulus per- 
sistent, of one to three rows of rather small cells; lid obliquely 
short-pointed, its height slightly exceeding its basal diameter, 
the cells in erect rows and scarcely elongate except in the point; 
calyptra cucullate, rather small, the apex smooth and dark col- 
ored; spores papillose, 30-50 in diameter. [Fic. 11.] 
TYPE LocaLity: Tyrol, Austria. 
DistRIBUTION: Gaspé coast, Quebec, to the Yukon River, and 
southward to Colorado. 
ExsiccaTAE: Macoun, Can. Musci 717, 604. 
ILLUSTRATIONS: Schwaegr. Suppl. 1!: pl. 28; B.S.G. Bryol. Eur. 
pl. 134. 
12. DesMATopon LaurERI (Schultz) B.S.G. Bryol. Eur. (18-20): 
Desmatodon 9. 1843 
Trichostomum Laureri Schultz, Flora 10: 163. 1827. 
Tortula bryoides Hook. in Drummond, Musci Am. 135. 1828. 
Autoicous, the male flower sessile just below the perichaetium, 
of eight or ten more or less stalked antheridia about 0.5 mm. long, 
with abundant, often longer, club-shaped paraphyses, enclosed by 
two or three ovate, entire, somewhat acute leaves, with the costa 
vanishing just below the apex: plants in compact tufts from a few 
millimeters to 2 cm. high, with somewhat branching stems more 
or less tomentose below; the lower stem leaves ovate, the upper 
longer, more or less erect-flexuous and twisted when dry, nearly 
