190 Evans: HEPATICAE OF PUERTO RIco 
According to Stephani, Spruce himself at one time acquiesced in 
the reduction, but apparently he changed his mind later because 
in his ‘‘ Hepaticae Elliottianae,’’ published shortly after his death, 
it is maintained that both species are distinct.* The specimens of 
Lejeunea chaerophylla, distributed in Hepaticae Spruceanae, have 
entire underleaves and perichaetial bracteoles, and to this extent 
differ from many of the West Indian forms of O. Szeberiana, but 
as the denticulation of these parts is always variable, this slight dif- 
ference can hardly be considered sufficient to separate the species. 
It will be seen from the descriptions given above that O. /unu- 
lata and O, Sieberiana are very closely related species. The most 
important difference between them is in the inflorescence, which is 
monoicous in one and dioicous in the other. Since the plants are 
rarely sterile this difference can usually be demonstrated. The 
characters derived from the vegetative organs are subject to so 
much variation that they must be used with caution in separating 
the species, and yet, supported by the inflorescence, they are of 
some importance. The postical margin of the lobe, for example, in 
O. Sieberiana is more regularly dentate than in O. /unulata and 
fails to show the deep and conspicuous sinus between its two 
middle teeth. The lobule also, in the monoicous species, is less. 
strongly inflated and more regularly denticulate along its free 
margin, and the leaf-cells have smaller trigones and intermediate 
thickenings. The underleaves afford differential characters which 
are a little more reliable than those drawn from the leaves; in 0. 
Sieberiana they are rounded and entire in the basal portion, and, if 
they are dentate at all, the teeth increase in size toward the plane 
apex ; in O. dunulata the basal portions often project outward as 
sharp teeth, while the revolute apex is very minutely denticulate- 
So far as the writer’s experience goes, O. Sieberiana is found at 
rather high altitudes (2,000 feet and above), while O. /wnulata 
occurs in the plains; and apparently this difference in habitat has 
been noted by other observers. 
Under the name Lejeunea (Odonto-Lejeunca) calcarata, Sprucet 
describes a plant from the Amazon to which he doubtfully refers 
the old Phragmicoma calcarata Mont.t This species was long 
* Jour. Linn. Soc. Bot. 30: 336. 1894. 
+ Hep. Amaz. et And. 146. 1884. 
ft Ann. Sci. Nat. Bot. II. 1g: 261. 843. 
