Evans: HEPATICAE OF PuERTO RICO 193 
the West Indies. Even as it stands the extremes of the genus 
are rather more diverse than is usual in the Lejeuneae, and it is 
possible that it should be still further subdivided ; for the present, 
however, it seems wisest to leave it intact. All of the species of 
Cyclolejeunea, so far as known, are confined to the American trop- 
ics and are found on living leaves or on the bark of trees. The 
genus may be characterized as follows: 
Cyclolejeunea gen. nov. 
Lejeunea p. p. G. L. & N. Syn. Hep. 1845. 
Leeunea subgenus Odonto-Lejeunea p. p. Spruce, Hep. Amaz. 
et And. 1884. 
Lejeunea subgenus Priono-Lejeunea p. min. p. Spruce, 1. c. 
Odontolejeunea p. p. Schiffn.; Engler & Prantl, Nat. Pflanzen- 
fam. 1893. 
Plants medium-sized to large, sometimes delicate in texture 
sometimes more robust, varying in color from pale green or 
whitish to brownish or olive green: stems prostrate and adherent 
to the substratum, sparingly to copiously branched : leaves con- 
tiguous to densely imbricated, the lobe widely spreading, plane or 
slightly convex, not revolute along the postical margin, falcate- 
ovate, broad at the apex and usually rounded or apiculate but 
never acute, margin varying from entire to coarsely and irregu- 
larly dentate ; lobule inflated and forming a distinct water-sac, 
keel more or less arched, free margin involute, tipped at the apex 
by a single cell bearing a marginal hyaline papilla at its proximal 
base ; leaf-cells sometimes delicate and scarcely thickened at the 
angles, sometimes with distinct trigones and intermediate thicken- 
ings ; ocelli usually but not invariably present : underleaves approx- 
imately orbicular in form, sometimes undivided, sometimes regu- 
larly bifid, sometimes undivided or bifid in the same species, at-~ 
tached by a short and scarcely arched line of insertion : inflores- 
cence usually dioicous: Q inflorescence borne on a more or less 
abbreviated branch or on a leading branch, innovating on one 
side, the innovation sometimes floriferous ; bracts unequally bifid, 
about as large as the leaves, lobule small but usually distinct ; 
perianth strongly flattened but with a distinct postical keel, broad 
and emarginate above, lateral keels more or less toothed, some- 
times winged : inflorescence occupying a shorter or longer 
branch ; bracts imbricated, diandrous: vegetative reproduction by 
means of disc-like gemmae borne on the margins of the leaves. 
(Name from xvxi0¢, a disc, and Lefeunea, in allusion to the 
gemmae). 
