1896,] North American Species of Plagiochila, 189 
tobe ‘obconic.” I have found that the shape of the perianth 
depends to a large extent upon the presence or absence of fer- 
tilization. In Swedish specimens of P. aspleniotdes collected 
by Dr. Arnell, some of the perianths with unfertilized archegonia 
are distinctly rounded at the base, while in specimens of P. po- 
relloides collected by Professor Underwood near Syracuse, New 
York, perianths with mature capsules are narrowed and sub- 
terete atthe base. It is apparent, therefore, that Lindberg’s 
point of distinction is of little real value. Dr. Schiffner?? 
3. Plagiochila Columbiana, n. sp.—Plate XV. figs. 1-10. 
Sterile, brownish or yellowish green, loosely caespitose; 
stems ascending, simple or pinnately branched, rarely dichot- 
®mous, often sparingly radiculose; leaves contiguous or im- 
bricated, widely spreading, broadly orbicular-ovate, antical 
margin decurrent, revolute, entire or occasionally bearing an 
acute lobe-like tooth, postical margin rounded at the base, 
plane or rarely reflexed, entire or irregularly I- to 3-toothed, 
apex broadly truncate, usually bearing a few scattered teeth; 
underleaves either minute and subulate or larger, lanceollate 
to ovate, acute, entire or irregularly toothed or lobed; eaf- 
cells polygonal, with thickened walls and prominent trigones. 
tems 1.5 to 3™ long, 0.4™" in diameter; leaves Pe pps long, 
1.1" wide; leaf-cells from middle of leaf averaging 0.041" In 
diameter. 
won, boulders subject to inundation; Rock Creek, near 
ishington, D. C., J. M. Holzinger. 
"general appearance P. Columbiana bears some resem- 
lines of its | 
P%ition of 
the lower ] 
ty Much lar 
* Plagiochile. The large underleaves described above 
