232 Evans : HEPATICAE OF PUERTO RIco 
sharply and irregularly denticulate or serrulate from projecting 
cells, the teeth along the postical margin a little blunter than else- 
where ; lobule inflated throughout, ovoid, 0.15 mm. long, 0.1 mm. 
wide, keel strongly arched, free margin straight or nearly so, invo- 
lute to beyond apex but usually appressed to lobe, sinus lunulate, 
apical tooth rather sharp and slightly curved ; cells of lobe slightly 
convex, averaging 15y at the margin, 21 # in the middle and 
25 xX 21 pat the base, rather thin-walled, with small but distinct 
trigones and occasional intermediate thickenings : underleaves dis- 
tant, broadly orbicular, 0.14 mm. long, 0.15 mm. wide, bifid about 
two thirds (to within a single cell of the radicelliferous region) 
with triangular acute lobes separated by a broad acute to lunulate 
on a very short branch without innovation ; bracts widely spread- 
ing, the lobe falcate-obovate, 0.5 mm. long, 0.35 mm. wide, apex 
apiculate or acute, margin as in the leaves but with rather more 
conspicuous and irregular teeth, lobule oblong to lanceolate, 0.18 
mm. long. 0.05 mm. wide, apex blunt to sharp, margin entire ; 
bracteole free, ovate, 0.35 mm. long, 0.2 mm. wide, bifid one third 
to one half with erect or connivent, acute to acuminate lobes and 
a narrow sinus, margin usually entire, sometimes with a single 
tooth on one or both sides; perianth triangular in outline with 
straight or somewhat incurved sides, 0.75 mm. long, 0.65 mm. 
wide, postical keel low and broad, apex deeply obcordate and 
with a short beak, lateral keels Sutendedl upward as rounded 
auricles, each developing in the upper part two distinct and deeply 
laciniate wings, the laciniae one to five cells long and one to four 
cells wide at the base, surface of perianth smooth or slightly 
roughened from projecting cells: ¢ inflorescence occupying. 4 
short branch ; bracts in one to six pairs, strongly inflated and 
shortly bifid, the lobe acute and slightly Seite the lobule 
blunt and entire, keel strongly arched, narrowly winged in the 
outer part, the wing composed of a single row of crenulate cells; 
bracteoles in lower part of spike, similar to the underleaves but 
smaller: mature sporophyte not seen (PLATE 12, FIGURES I-13). 
On roots of tree ferns. North slope of the Luquillo Moun- 
tains, Heller (4633). El Yunque, Evans (148). No. 148 may be 
designated the type. 
In the perianth of P. Helleri the sides are sometimes nearly 
straight instead of being strongly incurved as in the figured speci- 
men; the conspicuous wings, however, seem to be a constant 
feature although the laciniae vary considerably in length. Per- 
