152 American Midland Naturalist Monograph No. 6 



tose below about 1-3 cm high, slender; leaves of fertile stems 1-2 mm long, 

 rather distant, lance-ovate, acute, ascending to appressed, when dry somewhat 

 crispate, carinate, with revolute margins but not plicate, more or less spreading, 

 serrulate in apical half, scarcely decurrent; costa strong, brownish, percurrent 

 to somewhat excurrent; leaf cells mostly parenchymatous, rectangular to hexag- 

 onal to oblong above, incrassate, median cells strongly papillose on upper end, 

 about .003-. 006 X .015-030 mm, elongate-rectangular, apical cells narrower and 

 tendinjT to vermicular-hexagonal, basal cells looser, more or less rectangular, 

 up to .012 X .040-. 060 mm, smooth; inner perichaetial leaves ovate-triangular at 

 base with the costa excurrent into a subulate apex, the margin entire, the cells 

 rather lax; perigonial leaves erect-spreading, long-acuminate, serrate; seta about 

 2.5-3 cm long, erect, smooth, shining, reddish-brov.n, when dry flexuous; cap- 

 sule globose to ovoid-globose, faintly striate, about 2-2.5 mm long, brownish, 

 when dry sulcate and variously wrinkled, arcuate, cemuous, the neck sunken in, 

 about 4-6 rows of cells at the mou'.h of the capsule laterally elongate; peristome 

 double, the teeth 16, narrowly triangular-lanceolate, prominently articulate, 

 pellucid, oranoe to reddish-brown, divisural zigzag, distinct below; segments 

 narrow, about four-fifths as high as the teeth, mostly split apart; cilia three, 

 very short and rudimentary, the basal membrane comprising more than half 

 the height of the inner peristome, the segments and the upper part of the 

 membrane orange-pellucid, papillose-striate; spores globose, papillose, pellucid, 

 orange to reddish-brown, .01 8-. 025 mm, mature in June. 



On dripping rocks along streams, wet places, etc., from Virginia to Maine. 



Uncommon in our region. Allegheny Co.: In crevices of rocky bed of stream, ravine 

 of Power's Run, May 14, 1908. O.E.J, (figured). Lawrence Co.: Wet rocks in deep 

 lavine near Rock Point. June 26, 1909. O.E.J. 



4. Philonotis fontana [Linnaeus] Bridel 

 (Mnium fontanum Linnaeus; Bartramia fontana Swartz) 



Plate XXIX 



Cespitose, yellowish-green, sometimes quite glaucous, loose above but inter- 

 woven belov/ with a reddish-brown felt-like tomentum: stems erect, reddish, 

 slender, usually 2-6 cm high, densely fulvous-radiculose below, the innovations 

 usually whorled and giving the plants the appearance of being pleurocarpous; 

 leaves about 1.5-2 mm long, lance-ovate, acuminate, appressed when dry, 

 usually quite plicate on each side of the costa near the base, serrate above, 

 usually more or less revolute towards the base; costa strong, often percurrent 

 or even excurrent, usually reddish; basal cells elongate-rectangular to elongate- 

 hexagonal, loose, pale pellucid, about .008-. 012 (-.015) mm wide, the end- 

 walls often papillose, the cells in the acumen linear-vermicular, incrassate and 

 more or less papillose at both ends; perigonial leaves spreading, broadly tri- 

 angular-ovate, the inner often obtuse and rounded at the apex, the costa not 

 reaching the apex: seta dark red, 2-4.5 cm long; capsule ovate-globose, large, 

 brownish, thick-walled, striate, oblong, when dry and empty arcuate and ir- 

 regularly ribbed; operculum conic-convex, acute; peristome-teeth reddish-brown, 

 p>ellucid, lanceolate; peristome-segments nearly as long as teeth, narrow, carinate- 

 !y gaping, cilia three (two) about as long as segments; spores very slightly 



