24 Evans: HeEpaTICAE OF PUERTO Rico 
trate, sparingly and irregularly pinnate, the branches obliquely or 
widely spreading: leaves distant to subimbricated, the lobe erect 
and subparallel with the axis or slightly spreading, plane or some- 
what convex, oblong-lanceolate, 0.4 mm. long, 0.15 mm. wide, 
narrowed toward the base and attached by a short, slightly oblique 
line of insertion, margin irregularly crenulate from projecting cells, 
antical margin slightly curved, apex acute to abruptly acuminate, 
tipped with a single cell or more commonly with two or three cells 
in a single row, postical margin curved at about the middle of the 
leaf, usually forming an obtuse angle with keel; lobule ovate, 
strongly inflated (except in apical region), 0.15 mm. long, 0.1 mm. 
wide, keel strongly arched, more or less crenulate at least in outer 
part from projecting cells, free margin usually involute as far as 
apex, almost straight when explanate, passing beyond apex by a 
rounded to obtuse sinus to end of keel, apex acute, tipped with a 
single slightly curved cell; cells of lobe somewhat convex, thin- 
walled but with large trigones projecting slightly into cell-cavities, 
intermediate thickenings rare, cells averaging 23 x 16 y# at the 
edge of the leaf and 23 w in the middle; base of lobe showing a 
distinct group of four oblong cells, each about 30 » long and 9g rt 
wide ; ocelli none; cells of lobule with wavy outlines and no tri- 
gones, averaging 14 x 17 4: underleaves distant, basal portion 
quadrate, scarcely narrowed at line of attachment, 0.05 mm. 
long, marginal cells six, not bulging, divisions erect-spreading, 
consisting usually of three cells in a row, rarely two cells 
wide at base, with a spread of 0.06 mm.: inflorescence dioicous : 
? inflorescence borne on a short branch, innovating on one 
side with a simple and sterile innovation ; bracts obliquely spread- 
ing, scarcely complicate, unequally bifid, the lobe ovate, acute to 
acuminate, 0.4 mm. long, 0.2 mm. wide, margin subentire to irreg- 
ularly and sparsely dentate or spinulose, lobule ovate, 0.3 mm. 
long, 0.15 mm, wide, acuminate to blunt at the apex, margin as 
in lobes ; bracteole free or slightly connate at the base, oblong to 
subrotund, 0.35 mm. long, 0.15 mm. wide at base, bifid one third 
to one half with acute to acuminate divisions and acute sinus, 
margin as in bracts but usually less toothed ; perianth somewhat 
exserted, obovoid, 0.7 mm. long, 0.35 mm. wide, narrowed at the 
base, rounded to truncate at the apex and with a short beak, terete 
below, sharply five-keeled above, the keels rounded in the upper 
part and slightly roughened from projecting cells, not project- 
ing as horns:.¢ inflorescence terminal; bracts in a few pairs, 
large, rotund-galeate, compressed, truncate above, and scarcely 
bifid, with a row of hyaline, projecting cells htc keel A rae ee 2 
10-19). 
