554 Evans: HEpATICAE OF PUERTO RICO 
Bright green, sometimes becoming brownish or yellowish upon 
drying, growing in depressed tufts or more commonly mixed with 
other bryophytes: stems prostrate but not closely adherent to 
substratum, 0.04 mm. in diameter; branches widely spreading, 
sometimes with rudimentary leaves: leaves distant to slightly im- 
bricated, the lobe obliquely spreading, strongly convex and revo- 
lute along postical margin, ovate to orbicular-ovate, slightly or 
not at all falcate, 0.25 mm. long, 0.17 mm. wide, attached by an 
almost longitudinal line of insertion except at antical base, margin 
entire, antical margin more or less curved, sometimes arching 
partly or entirely across axis, postical margin somewhat curved 
in explanate leaves, apex broadly rounded ; lobule sphaero-ovoid, 
0.17 mm. long, 0.12 mm. wide, strongly inflated, keel, convex 
and strongly arched, roughened from projecting cells, free mar- 
gin straight and entire, involute to base of apical tooth, sinus 
broad and shallow, apical tooth straight and slender, forming a 
continuous line with the inner part of the free margin when 
flattened out; cells of lobe convex, averaging g p at the mar- 
gin of the lobe and 14 x 12 y in other regions, either thin- 
walled throughout or with minute but more or less distinct tri- 
gones; ocelli none: underleaves distant, orbicular, 0.08 mm. 
long, subcuneate at the base, rounded or very rarely bicrenulate 
at the apex, margin entire; rhizoids commonly scanty, growing 
from the bases of the underleaves: inflorescence dioicous: ¢ in- 
florescence with a sterile innovation, bracts scarcely complicate, 
shortly and unequally bifid, the lobe broadly orbicular-ovate, 0.4 
mm. long, 0.3 mm. wide, entire, rounded at apex, lobule lanceolate, 
acute, 0.3 mm. long, 0.07 mm. wide; bracteole free or nearly 5°, 
obovate, strongly convex postically, 0.3 mm. long, 0.25 mm. 
wide, bifid one fourth or less with broad rounded lobes and obtuse 
sinus; perianth about half exserted, oval to obovoid, 0.7 mm. 
long, 0.35 mm. wide, rounded at the apex and with a rather long 
and slender beak, narrowed toward base, sharply five-keeled in 
the upper part, the antical keel a little lower than the others, keels 
sometimes obscurely winged, surface of perianth smooth : 8 in- 
florescence usually intercalary on a leading branch, bracts in one 
to four pairs, strongly concave and inflated, shortly and_ sub- 
equally bifid, the lobes and lobules rounded; bracteoles (when 
present) similar to ordinary underleaves ; antheridia and mature 
sporophytes not seen (f/. 27, f. 10-23). 
On bark of trees, rarely on living leaves. El Yunque, £va"s 
(21 p.p., 46 p.p.). The type-specimens were collected by Spr“? 
in Brazil and distributed in Hepaticae Spruceanae. Other stations 
for the species are the following : Cuba, Wright; Venezuela, Moin; 
St. Vincent, E//ott. 
