. 
Evans: TAXILEJEUNEA PTEROGONIA 121 
on the same stem the wings on the two. lateral keels and on one 
ventral keel run out into points, the dorsal keel and the other 
ventral keel being almost wingless; in a third perianth on the 
same stem all five keels bear more or less pointed wings. The 
perianths described include the most complex wings observed, 
and it will at once appear that these never exhibit the sharply 
dentate or ciliate condition so often found in T. pterogonia, although 
the less complex conditions of that species may be approached. 
3. Taxilejeunea densiflora sp. nov. 
Pale yellowish or whitish green, growing in loose mats, pure 
or in admixture with other bryophytes: stems mostly 0.2-0.25 
mm. in diameter, irregularly branched, the branches mostly 
shorter and with smaller leaves than the stem, usually bearing 
sexual organs and sometimes more or less. subdivided: leaves 
loosely imbricated, the lobe obliquely spreading, plane to some- 
what convex, scarcely falcate, ovate, mostly 1-1.5 mm. long 
and 0.8-1.2 mm. wide when well developed, dorsal margin aching 
across the stem and rounded to cordate at the base, slightly 
curved, ventral margin slightly curved and forming a wide angle 
with the keel, apex rarely obtuse, mostly acute or apiculate and 
occasionally tipped with a row of two cells, margin minutely but 
—e crenulate from projecting cells especially toward the 
ex and occasionally with one or two larger blunt or sharp teeth in 
this vicinity; lobule inflated aris asa narrowly to broadly 
ovoid, about 0.15 mm. long and 0.06—0.1 mm. wide when well 
developed, keel straight to slightly kt free margin involute 
to beyond the apex, sinus and apical tooth as in allied species; 
lobule usually poorly developed; cells of lobe about 23 u wide 
along the margin, 44x 32 uw in the middle and 55x 34 u at the 
base, thin-walled throughout or with minute trigones having 
concave sides, intermediate thickenings, scarcely or not at all 
developed, cuticle smooth; underleaves contiguous to loosely 
imbricated, convex from below, the lateral margins often involute, 
orbicular, mosthky 0.8-1.2 mm. long, bifid one fourth or less with a 
narrow, usually sharp sinus and broad, acute to obtuse, con- 
tiguous or overlapping divisions, cordate to auriculate at base, the 
auricles sometimes contiguous but rarely if ever overlapping, 
margin minutely crenulate from projecting cells; inflorescence 
autoicous: 2 inflorescences borne on a more or less elongated and 
usually repeatedly floriferous branch-systems, each subtended by 
one or, rarely, two innovations, the latter often bearing a second 
flower after a single vegetative leaf and underleaf, complicated 
