OF WESTERN PENNSYLVANIA 225 



H. cladorhizans but quite similar in general appearance : leaves 

 about 1.0-1.1x0.4-0.5 mm., quite concave, broadly oblong- 

 ovate, obtuse, entire at apex ; median leaf-cells linear, the alar 

 quadrate and numerous; costa none or very rudimentary: seta 

 erect, long ; capsule erect, short-ovate to elliptic, narrow- 

 mouthed, about 2.5X0.6 mm. ; lid rather long and with a slender 

 curved rostrum ; annulus large, early deciduous ; peristome- 

 teeth long, lance-linear, closely articulate, the segments some- 

 what shorter, linear-subulate, free from the teeth, the teeth 

 densely papillose above ; spores mature in fall or early winter. 



On bases and roots of trees in moist situations, often near 

 water-courses ; northern Europe, Asia, and, in the United 

 States from Missouri to Pennsylvania and southwards. Ap- 

 parently rare, or entirely absent from our region, but occurs 

 in Ohio and in Eastern Pennsylvania. 



2. Entodon cladorhizans (Hedwig) C. Mueller. 



(Cylindrothecium cladorhizans Schimper ; Neckcra cladorhizans 

 Hedwig). 



(Plate XXXII) 



Cespitose in wide tufts, brightly lustrous, yellowish-green : 

 stems compressed, somewhat pinnately branched, rather 

 acuminate and sometimes up-curved at the apex ; branches 

 complanate and spreading widely from the stem, more or less 

 acuminate to attenuate at the apex, where sometimes rooting; 

 leaves loosely imbricate, very concave, non-plicate, narrowed 

 at the apex, margin plane or narrowly revolute below, apex 

 sub-acute, faintly serrulate, usually turned slightly backwards; 

 leaves ovate to oblong, about 1-2 mm. long by one-half as wide; 

 costa double, short and indistinct, or none ; median leaf-cells 

 long-linear, prosenchymatous, smooth, with firm and hyaline 

 walls, the alar hyaline to somew r hat reddish, incrassate, quad- 

 rate-rectangular in a triangular patch of 6-8 rows depth, bord- 

 ered by a few intermediate, sub-quadrate to sub-vermicular 

 cells, the apical cells shorter and rhombic : seta erect, smooth, 

 sinistrorse, rich castaneous in color, lustrous, about 8-12 mm. 

 long; capsule about 4-6:1, oblong-cylindric, tapering abruptly 

 to the seta, smooth, not sulcate when dry, castaneous, narrowed 

 somewhat at the mouth, 2.5-3.5 mm. long; annulus early de- 

 ciduous, large, pulri-seriate with incrassate quadrate cells ; 

 exothecial cells yellowish with thin walls, rectangular to ob- 

 long, towards the rim suddenly much smaller and incrassate, 

 more or less laterally oblong under the annulus ; operculum 

 conic-rostrate, about 0.4-0.6 mm., long, often apiculate ; peris- 

 tome double, deeply inserted, teeth light-castaneous, about 16- 

 20-articulate, below lightly papillose-striate in variously diver- 

 gent or radiating lines, not finely transversely striate as in 



