147 
lose at tip; leaves closely imbricate when dry; branch leaves 
lanceolate, 1.9X0.6 mm., gradually narrowly acuminate, entire 
or slightly serrulate at apex, concave; costa double, extend- 
ing nearly 14 length of leaf; median cells oblong-hexagonal with 
length 6 times diameter; alar and basal cells quadrate, chlor- 
ophyllose ; stem leaves larger, ovate-lanceolate : monoicous ; 
male branches frequent ; antheridia numerous, oblong-ovoid, stipi- 
tate; perigonial leaves bordered by a row of elongated cells, inner 
oblong-obovate, short acuminate: perichaetium 3.5 mm. long; 
the outer leaves sheathing at the base with squarrose tips ; the in- 
ner erect, oblong-lanceolate, long acuminate, entire; costa double, 
ending below the middle; leaf-cells linear above, rhomboidal be- 
low. Sporophyte 10-20 mm. high; seta light reddish brown ; 
capsule brown, 2.5-3 mm. long, 5: 1, cylindric-ovoid, contracted 
below the mouth when dry; operculum  long-conic, ob- 
tuse; annulus compound, of 3 rows of cells; peristome 0.3 mm. 
long; teeth linear-lanceolate, reddish brown, closely and regularly 
articulate, nodulose at articulations above, bordered the entire 
length by the adherent segments ; spores tuberculate, 21, matur- 
ing in autumn. 
Type locality, Missouri, near St. Louis (Drummond). 
On trees, limestone rocks, etc., New Jersey, Virginia, Pennsyl- 
vania, Ohio, Missouri ; Canaan Forks, New Brunswick (J. Moser). 
Not common. 
ILLustRATIONS.—Hook. & Wils. 1. c.; Sull. Icon. Musc. AJ. 96. 
ExsiccATi.—Drumm. Musc. Am. (S. States) 95, (Type); 
Sull. Muse. Allegh. 79; Sull. & Lesq. Musc. Bor. Am. (Ed. 1) 
265, (Ed. 2) 391. 
This species is readily distinguished from all others by its nar- 
rowly acuminate leaves and the adherent segments of the inner 
peristome. The locality given in the Manual of Lesq. & James 
from the western United States. The male and female organs seem 
to have a tendency to appear in alternate seasons on the same plant. 
DOUBTFUL OR EXCLUDED SPECIES. 
Entopon Macouxi: C. Muell. & Kindb. in Macoun, Cat. Can. Pl. 
6: 177. 1892. 
