ure Evans: HEpATICAE OF PuERTO RICO 
relatively large. As a rule two types of leaves are developed, 
large and normal leaves with typical lobules and much smaller 
leaves with rudimentary lobules, and they seem to be unconnected 
by intermediate types (FIGURES 17 and 18). The leaf cells vary 
from slightly convex to conical, and none are ever differentiated 
as ocelli or hyaline cells. Their walls are exceedingly thin and 
show no trigones, although a strongly conical cell will sometimes 
show a slight thickening at the apex of the cone. Corresponding 
with the shape of the cells the margin of the lobe varies from 
crenulate to denticulate. 
A monoicous inflorescence seems to be almost invariably the 
rule in the genus. Sometimes the male inflorescence is borne on a 
distinct branch with strongly modified bracts, but it seems to be 
more usual for the antheridia to be borne in the axils of the leaves 
below a female inflorescence or even in the axil of one of the 
perichaetial bracts. Under these circumstances the perigonial 
bracts are scarcely modified. The female inflorescence always 
bears one or two subfloral innovations, which may or may not be 
floriferous. The perichaetial bracts are very much like the leaves, 
except that the lobules tend to be plane and show differences in 
the apical region. The perianth is obovoid and inflated, at least 
near the apex. Sometimes there are no signs of keels; sometimes 
five keels, more or less marked, can be distinguished. In some 
cases the beak of the perianth is indistinct or practically obsolete. 
The sporophyte is essentially like that of Cololejeunea. The genus 
may be characterized as follows: 
Aphanolejeunea gen. nov. 
Plants very delicate, pale green, often becoming whitish when 
dry: stems prostrate, sparingly branched: leaves distant to con- 
tiguous, the lobe often concave in the outer part, widely spreading, 
oblong to lanceolate, rounded to acuminate at the apex, the 
margin usually crenulate or denticulate from projecting cells; 
lobule inflated, the involute free margin often including the apex, 
sinus lunulate, apical tooth consisting of a single projecting cell, 
separated by a slight indentation from the usually less distinct 
proximal tooth, hyaline papilla distal to the apex, situated in the 
sinus but slightly displaced to the inner surface, keel arched; 
cells of lobe uniform, convex to conical, usually thin-walled 
throughout: underleaves wanting: inflorescence mostly autoicous 
