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556 Evans: HEpATICAE OF PUERTO RICO 
papilla is borne at its distal base (f/. 27, f. 78, 79). In Enosmole- 
jeunea the papilla is likewise borne at the distal base of the apical 
tooth but the tooth itself is short and rather bluntly pointed, pro- 
jecting only for a short distance beyond the adjoining cells (p/. 22, 
7. O). 
Of all the genera to which Cyrtolejeunca holostipa has been 
referred, it is perhaps most closely related to Microlejeunea, from 
which its undivided underleaves and peculiar lobules should doubt- 
less exclude it. From Harpalejeunea it differs not only in these 
characters, but also in its rounded obliquely spreading leaves and 
in its lack of ocelli; from Euosmolejeunea it differs in its small size 
and green color, as well as in its small leaf-cells with delicate 
walls. There are no Puerto Rico species with which it could 
readily be confused. 
* 
EUOSMOLEJEUNEA 
The typical members of the genus Ewosmolejeunea are among 
the most easily recognized Lejeuneae of the tropics. They are 
fairly robust for species with bifid underleaves and are usually 
characterized by a peculiar yellowish green color and by a rather 
pronounced odor. At first glance they perhaps bring to mind 
Omphalanthus filiformis, which, however, is even more robust and 
is further distinguished by its undivided underleaves and by its 
perianth without keels. The leaves in Ewosmolejeunea have well- 
developed lobes and small lobules ; the lobes are broad and spread 
widely from the stem, they are more or less convex and are com- 
monly broad and rounded at the apex and their margins are entire 
or nearly so. The lobules are strongly inflated, and their free 
margins are involute to beyond the apex; the latter is tipped by 
a single slightly projecting cell, which is straight and not sharply 
pointed. The hyaline papilla is at the distal base of this project 
ing cell. The leaf-cells are firm and are frequently convex; 
trigones are conspicuous, but intermediate thickenings are wanting 
or exceedingly rare. Ocelli are also wanting. The underleaves 
are large and orbicular, in certain species extending almost to the 
apices of the lobes; they are commonly cordate at the base, and 
the apical sinus varies from lunulate to acute. In a few species 
the underleaves are much smaller and are cuneate at the base; 1 
one or two species which have been referred to the genus, the 
