506 Evans: HeEpaTICAE OF PUERTO RIco 
outer part; bracteoles limited to base of spike, similar to ordinary 
underleaves, but smaller and with more erect divisions : antheridia 
in pairs (p/. 25). 
On living leaves. Cayey, Evans (71 Pp. f.). 
The Puerto Rico specimens of L. hamulata agree closely with 
those distributed in Hepaticae Cubenses. Unfortunately they show 
no perianths and the description of this organ as given above is 
taken entirely from Schiffner. In all other respects the specimens 
are well developed. 
The close relationship which exists between the present species 
and L. stenophylla has already been commented upon by Schiffner. 
L. hamulata is the larger of the two species and differs also in its 
broader and less acuminate lobes with sharply denticulate margins. 
It must be acknowledged, however, that poorly developed speci- 
mens are sometimes difficult to determine. 
In the original description of Z. hamudata the lobule is said ” 
be “cylindrico-convolutus apice duobus dentibus validis hamatis 
conniventibus foramen rotundum includentibus armatus.” One of 
the teeth referred to is evidently the curved cell at the apex of the 
lobule, the other is apparently the fold at the junction of lobule 
and lobe. Until the lobule is flattened out by pressure this fold 
often resembles a tooth in a marked degree. A lobule of this 
character, although not unusual in Drepanolejeunea, is, according 
to Schiffner, almost unique in Leptolejeunea. He emphasizes it 
fact as one of the most important differences between L. hamulata 
and L. stenophylla. It is evident, however, from a study of the 
Puerto Rico specimens of the latter species that a normal \obule 
is built up on essentially the same plan as in Z. hamulata. Un- 
fortunately normal lobules are somewhat unusual and are largely 
replaced by rudimentary structures in which the true lobular char- 
acters are not apparent. In the Cuban specimens normal lobules 
are still more infrequent but may be demonstrated by car eful ga 
Aside from their lobules Z. stenophylla and L. hamulata resem A 
each other closely in their antheridial spikes, in the posse 
a subfloral innovation, in their perichaetial bracts and bracteo' ® 
and apparently also in their perianths. Most of these peculiarities 
will distinguish them from L. exocellata and L. elliptica. 
se ‘ f 
In addition to the ordinary method of reproduction, the fou 
