550 Evans: -HEPATICAE OF Puerto Rico 
curved and arching partly or entirely across axis, postical margin 
straight or slightly curved, apex abruptly apiculate to cuspidate, 
ending in a single row of from two to five cells, on leaves of 
slender branches sometimes obtuse ; lobule ovoid, 0.15 mm. long, 
0.08 mm. wide, strongly inflated, abruptly constricted in outer 
part, thus forming a curved and narrow passage-way leading into 
the water-sac, keel strongly arched, smooth or nearly so, free 
margin either involute or appressed to lobe, passing beyond apex 
by a shallow sinus to end of keel, apical tooth slightly curved ; 
cells of lobe plane or nearly so, averaging 13 x 11 y, scarcely 
varying in size in different parts of the lobe, walls slightly thick- 
ened with scarcely evident trigones and occasional intermediate 
thickenings ; ocelli commonly two, placed end to end at the base 
of the lobe, 23 » long and 14” wide: underleaves distant, broadly 
obcordate, 0.05 mm. long, 0.07 mm. wide, narrowed toward base, 
bifid about one third with an obtuse sinus and broad, diverging, 
rounded or truncate lobes, each about four cells wide at base and 
three cells long ; rhizoids scanty, not growing from a disc : inflo- 
rescence dioicous: 9 inflorescence sometimes on a leading branch, 
sometimes on a short branch, innovating on one side with a com- 
monly sterile innovation ; bracts obliquely spreading, complicate, 
unequally bifid, the lobe ovate to obovate, 0.4 mm. long, 0.25 
mm. wide, apex obtuse to rounded, margin more strongly crenu- 
late or denticulate than in the leaves, keel often with a narrow 
entire wing one or two cells wide, lobule similar in shape to lobe, 
0.35 mm. long, 0.19 mm. wide, apex sometimes retuse, margin 
slightly and irregularly crenulate or denticulate ; bracteole slightly 
connate with one bract, oblong-obovate, 0.3 mm. long, 0.25 mm. 
wide, bifid about one third with slightly diverging blunt divisions, 
margin as in lobule; perianth about half exserted, oblong, 0.6 
mm. long, 0.35 mm. wide, slightly narrowed toward base, trun- 
cate above and with a short beak, sharply five-keeled except in 
basal region, the keels narrowly winged in the upper part with 
dentate to spinose wings, the projections consisting of from one to 
three cells: ¢ inflorescence and mature sporophyte not seen ( pl. 
20, f. 12-24). 
On bark of trees. North slope of the Luquillo Mountains, 
Heller (4763 p. p.). Also known, in sterile condition, from the 
following localities: Cuba, Wright; Santo Domingo, Zggé”s’ 
Trinidad, Crueger. 
Although the writer has been unable to secure authentic speci- 
mens of //. uncinata, his determination of the species has been 
confirmed by Herr Stephani. The description given above SUP~ 
