30 Evans: HEpATICAE OF PUERTO RICO 
widely spreading : leaves distant to subimbricated, the lobe sub- 
erect or obliquely spreading in the lower part, widely spreading 
above, convex, falcate-lanceolate, 0.35 mm. long, 0.08 mm. wide, 
somewhat narrowed toward the base and attached by an almost 
longitudinal line of insertion, margin subentire or slightly crenulate 
or denticulate from projecting cells, rarely with a larger blunt tooth 
a _sisneatlaal 
near end of keel, apex long-acuminate, ending in a row of two or 
three cells; lobule strongly inflated at base and along keel, 
broadly ovate, 0.15 mm. long, 0.1 mm. wide, keel strongly arched, 
slightly roughened in outer part from projecting cells, free margin 
plane and appressed to lobe, passing beyond apex by a lunulate 
sinus to end of keel, apical tooth strongly curved ; cells of lobe 
somewhat convex, their walls slightly but uniformly thickened, 
averaging 19 x 14 4; ocelli commonly two, one at the base of the 
lobe, the other at about the middle, indistinct: underleaves distant, 
basal portion quadrate or rectangular, 0.03 mm. long, marginal 
cells six, divisions obliquely to widely spreading (up to 0.07 mm.), 
each consisting of two or three cells in a single row, rarely two 
cells wide at base: inflorescence dioicous: @ inflorescence borne 
on a very short branch innovating on one side with a simple 
and sterile innovation ; bracts obliquely spreading, unequally bifid, 
the lobe ovate, 0.35 mm. long, 0.15 mm. wide. long-acuminate, 
the margin coarsely and irregularly dentate or spinulose-ciliate, 
usually with from four to seven teeth, lobule irregular in shape, 
0.25 mm. long, 0.08 mm. wide, acute to acuminate, margin as in 
lobe, but usually with fewer teeth (mostly one to five); bracteole 
connate on one side, ovate, 0.3 mm. long, 0.15 mm. wide, bifid 
about one third with erect, subacuminate lobes and narrow sinus, 
margin as in bracts, usually with from five to twelve teeth in all: 
perianth broadly obovoid, 0.4 mm. long, 0.3 mm. wide, gradually 
narrowed toward the base, truncate above and with a short beak, 
terete below, sharply five-keeled in upper part, the keels project- 
ing outward as subacute, slightly dentate horns; ¢ infloresence 
unknown ( p/. 3, 7. 9-77). 
On rotten wood. North slope of the Luquillo Mountains, 
Ffeller (1139). El Yunque, Evans (4, 196). 
The type-specimens of D. didens are in the Lindenberg her- 
barium at Vienna. They were preserved there under the name 
“Lejeunea hamatifolia” until Stephani proved their distinctness. 
Nothing definite seems to be known as to where they were col- 
lected, their label reading simply (according to Stephani) “ in cor- 
tice peruv.,” but it is probable that they came from tropical 
America. The species does not seem to be uncommon in the 
Luaquillo Mountarns. 
