220 Evans: HEPATICAE OF PUERTO RICO 
rounded at the apex, and a broad obtuse to lunulate sinus, margin 
subentire to crenulate from projecting cells, sometimes angular- 
unidentate on the sides : inflorescence autoicous: 92 inflorescence 
borne on a very short branch without innovation, the leaves of 
the branch being usually reduced to a rudimentary leaf and un- 
derleaf but sometimes with a pair of normal leaves interpolated 
between the rudimentary leaf and the involucre; bracts widely 
spreading, the lobe obovate, 0.6 mm. long, 0.35 mm. wide, 
rounded to subacute at the apex, margin as in the leaves, lobule 
oblong, usually blunt, 0.35 mm. long, 0.12 mm, wide, margin 
subentire ; bracteole free, ovate, 0.6 mm. long, 0.35 mm. wide, 
bifid about one half with acute lobes and a narrow sinus, margin 
as in the leaves but with rather more irregular teeth; perianth 
triangular in outline with nearly straight sides, 0.75 mm. long, 
0.6 mm. wide in broadest part, postical keel broad and rounded, 
apex truncate, slightly indented in the middle, beak obsolete, lat- 
eral keels extended upward as rounded auricles and bearing above 
the middle two interrupted and very narrow, denticulate wings, each 
tooth one or two cells long, surface of perianth smooth or nearly 
so: inflorescence occupying a short branch; bracts in one to three 
pairs: mature sporophyte not seen (PLATE I1, FIGURES 18-28). 
On a rotten log, Evans (103 p. p.). Originally collected by 
Breutel on St. Kitts, the type-locality, and recently found by Britton 
and Cowell on the same island. Also known from Dominica, A//oit. 
The most striking character of P. aemula is the very abrupt 
dilation of the lobe just beyond the lobule; this is sometimes so 
marked that a distinct passage-way is left between the base of the 
lobe and the axis (FIGURE Ig), giving the plant a most peculiar 
appearance. The marginal teeth or crenulations of the under- 
leaves, although not constant, should also be especially noted. 
In the female inflorescence the denticulate bracteole and the 
slightly retuse perianth with obsolete beak are perhaps the most 
important features, when comparing P. aemula with its immediate 
allies. Certain of these peculiarities are not clearly shown in the 
figures published by Spruce. 
According to Gottsche, the leaves of P. aemula are coarsely 
serrate and the lateral keels of the perianth are sometimes mi- 
nutely and sparingly ciliate and sometimes nearly entire. In his 
description of L. va/canica, Spruce calls attention to its close rela- 
tionship with Gottsche’s species but separates it because its leaves 
are minutely crenulate or serrulate and its perianth is subdenticu- 
