552 Evans: HeEpaTICAE OF PUERTO RICO 
averaging 14 in diameter at edge and 18 x 16 » elsewhere, thin- 
walled, trigones and occasional intermediate thickenings small but 
distinct; ocelli commonly two, placed end to end at the base of 
the lobe, 30 long, 21 » wide: underleaves distant, broadly ob- 
cordate, 0.07 mm. long, 0.08 mm. wide, narrowed toward base, 
bifid one fourth to one third with a shallow lunulate sinus and 
broad, diverging rounded lobes, each five or six cells long and four 
or five cells wide at base, margin obscurely crenulate from project- 
ing cells; rhizoids numerous, rarely growing from a rudimentary 
disc : inflorescence not seen (f/. 27, f. 1-9). 
On living leaves. El Yunque, Evans (20 f. p., 160 P. p.). 
Although H. heterodonta is known in sterile condition only, its 
foliar characters are so peculiar that it can hardly be confused with 
other members of the genus. When the leaf-margins are only 
slightly crenulate, the species bears some resemblance to 1. u7- 
cinata, but even on such specimens it is usually possible to find 
leaves with more strongly marked teeth, and the leaf-cells are con- 
stantly a little longer than in Stephani’s species and have thinner 
walls with more evident trigones. The marginal spines of 7. 
heterodonta are less frequent on robust stems than on slender 
branches. : 
Apparently Lejeunca ( Harpalejeunea) tridens Besch. & Spruce : 
is closely related to the present species. Z. ¢ridens is likewise 
West Indian ; it was originally known from Guadeloupe, but has — 
since been reported by Spruce from the neighboring island of 
Dominica.+ The leaves of this species, as its name implies, are 
almost constantly tridentate and the teeth are usually long and 
slender enough to be called spines. Judging from the published 
figures of L. tridens, the regularity of these foliar teeth or spines 
gives the plant a very different appearance from what we find in 
Hf. heterodonta. L. tridens differs, also, in its place of growth and 
in its thick-walled leaf-cells. 
CYRTOLEJEUNEA 
Attention has already been called to Lejeunea holostipa Spruce — 
a species originally placed by its author in the subgenus are 
Lejeunea and afterwards transferred to Microlejeunea. This inter- 
* Bull. Soc. Bot. France, 36: clxxxi. f/. 77. 1890. 
T Jour. Linn. Soc. Bot. 30: 341. 1894. 
