1897 | NORTH AMERICAN SPECIES OF AMBLYSTEGIUM 277 
est cells midway between cortex and central strand: capsule 
pale at maturity before dehiscence, usually brick red to chestnut 
‘brown when empty, 2 to 5™™ long, subcylindric or gradually 
widening to the mouth, incurved from an erect base to arcuate, 
more or less constricted below the mouth when dry; collum one- 
third to one-half the length of the sporangium; cells of exo- 
thecium parenchymatous on the concave side, 25" wide by 474 
long, varying in width from 17 to 43m, and in length from 21 to 
77, longer on the convex side and more or less prosenchymatous, 
especially in the lower half of the sporangium, 25.5 wide by 
53-5@ long, ranging from 15 to 35" wide and from 25 to 120m 
long, five to seven rows of cells under the mouth isodiametric, 
17 to 25.5win diameter, usually about two rows next the annulus 
transversely elongated, 8.5 to 15m long by 17 to 30 wide; cell 
walls 3 to 4m thick; stomata numerous, éwenty-five to eighty to 
the capsule, 78.54 wide by 47 long, scattered; peristome teeth 
orange or reddish-brown below, margined, margin narrow at base 
widening above into the hyaline tip, serrulate in upper third, 
transversely striate on the back in the lower half, papillose above, 
occasionally having the striz oblique or irregular in small areas 
near the middle; endostome pale, scarcely equaling the teeth, 
papillose throughout, membrane three-fourths the length of the 
segments, the latter lanceolate, carinate, split along the keel 
between the articulations, not gaping, cilia two or three, shorter 
than the segments, nodulose or subappendiculate ; operculum 
conic and acute or apiculate from a highly convex base; annu- 
lus broad, of two to three rows of cells: spores finely tubercu- 
late, 16 to 264; calyptra small, one-fourth to one-half the length 
of the capsule, split one-third its length. 
Has.: On rocks and earth in and along streams. Type 
locality Sweden. 
Europe, and North America: New Brunswick, Newfound- 
land, Quebec, Ontario, New York, New Jersey, Ohio, Michigan, 
and Wisconsin. 
The leaves of this species, usually not acuminate, with entire margin, 
broad blunt apex and strong costa vanishing in the tip, are generally suf- 
