1903 | ODONTOSCHISMA MACOUNIT AND ITS ALLIES 343 
stems sparingly and irregularly branched, 0.25™™ in diameter, 
prostrate with ascending tips; branches all postical; rhizoids 
scanty: leaves distant to loosely imbricated, plane or slightly 
concave, varying in shape from orbicular to oblong, 0.7~—1.4™™ 
long, 0.75-1.3™" wide, distinctly margined, attached by an 
oblique line of insertion, slightly decurrent antically but not 
dilated at postical base, margin entire, apex commonly rounded, 
sometimes truncate, emarginate or bilobed: median and basal 
leaf-cells 20m in diameter, thin-walled and with minute but dis- 
tinct trigones; cell cavities polygonal with rounded angles; 
marginal cells 14 X 23m, forming one to four concentric rows and 
often arranged in radial rows as well, their walls more or less 
uniformly thickened with indistinct trigones ; cuticle somewhat 
thickened, smooth or minutely verruculose: underleaves more 
or less persistent, linear to subulate in shape, 0.15™™ long, 0.05™™ 
wide, shortly bifid at the apex; slime papillae borne on the mar- 
gin and more rarely on the postical surface, short-lived: inflo- 
rescence dioicous: @ inflorescence on a short branch; involucral 
leaves in about three rows, those of the innermost row 1™™ long, 
0.5™" wide, ovate, bifid about one-half with slender spreading 
acuminate lobes and narrow sinus, margin entire or with one or 
two slender lobe-like teeth below the middle; leaves of outer- 
most row smalier and relatively broader, rounded or slightly 
bifid at the apex, margin entire; leaves of middle row inter- 
mediate in character; perianth linear-ovoid, 3™" long, 0.9™™ 
wide, slightly contracted at the base and at the apex, obtusely 
three-keeled in lower part when young, terete when old, plicate 
in upper part, mouth irregularly lobed or cleft, the lobes sub- 
entire to short-setulose, the setae rarely more than one cell 
long: 4 inflorescence occupying a short branch; bracts in about 
six pairs, complicate, shortly bifid with obtuse lobes and sinus, 
inflated near the antical base and commonly with a short and 
often inflexed tooth at about the middle of the antical margin; 
bracteoles larger than the ordinary underleaves, ovate, more or 
less distinctly bifid with subulate lobes; antheridia borne singly : 
capsule oval; spores brownish, 12 in diameter, minutely ver- 
ruculose; elaters gu in diameter, bispiral: gemmae wanting. 
