152 
Exsiccati.—Macoun, Can. Musc. 626. (Pylaisia filart-acumi- 
nata.) : 
2. PYLAISIELLA SUBDENTICULATA (Schimp.) Kindb. Can. Rec. Sci, 
1894: 22. 1894. 
Pylaisia subdenticulata Schimp. Bryol. Eur. fasc. 46-47. 1851. 
Pylaisia denticulata Sull. in A. Gray Man. Ed. 2: 52. 1856. 
Gametophyte darker green than the last, scattering or in thin 
mats, often closely intermixed with other species ; stems 1—3 cm. 
long, irregularly divided, subpinnately branching ; branches very 
short, usually less than 5 mm. long ; branch leaves erect-spread- 
ing, ovate-lanceolate, 0.7—1X0.2-0.35 mm., gradually long- 
acuminate, more or less denticulate especially above, concave, 
ecostate or costa thin, short and double ; median cells 6-8: 1; 
quadrate alar cells numerous : perigonial leaves ovate-lanceolate, 
acuminate, concave; antheridia oblong: perichaetium 1.5—2 mm. 
long, loosely sheathing ; inner leaves ovate-lanceolate, gradually 
or abruptly narrowed to a long point, more or less denticulate 
above, ecostate; leaf-cells linear-fusiform above, broader and 
rhomboidal below. Sporoplhyte 8-17 mm. high; seta brown; 
capsule brown, cylindric, 1.5-2 mm. long, 4~5: I; operculum 
conic, short-rostrate ; annulus very narrow, consisting of a row of 
isodiametric polygonal cells and a row of vesicular cells that often 
come off with the operculum ; teeth of peristome linear-lanceolate, 
orange, closely and regularly articulate, submoniliform and 
granulose above ; segments linear-lanceolate, a little longer than 
the teeth, more or less split above; cilia lacking ; spores yellow- 
brown, minutely roughened, 10-125, maturing in summer or 
early autumn. 
Type locality American (Sullivant). 
On trees. New York and New Jersey (Austin); Maryland 
(Holzinger); Ohio (H. J. Biddlecome) ; Athens, Ill. (Hall); New 
Mexico (E. O. Wooton). 
ILLUSTRATIONS.—Sull. Icon. Musc. A. 87. 
Exsiccati.—Sull. & Le3q. Musc. Bor. Am. (Ed. 2) 382. 
Very close to P. polyantha, but distinguished by the reduced 
size, rostrate operculum, absence of cilia and numerous quadrate 
alar cells. 
