Evans: HEPATICAE OF PUERTO RICO 279 
never found in the portion of the lobe which covers over the water 
sac. The lobule is inflated throughout its entire extent and the 
free margin lies in contact with the lobe as far as the proximal 
tooth. This is usually a little more prominent than the apical 
tooth, which rarely shows clearly without flattening out the lobule. 
In the rudimentary leaves the lobe is shorter and narrower than in 
normal leaves and is sometimes reduced to a width of only two 
or three cells. The lobule in such leaves is merely a minute basal 
fold, sometimes consisting of asingle cell. The perigonial bracts 
are also much more rudimentary in structure than in normal leaves 
and in extreme cases may be even shorter than the leaves just 
described. These bracts can afford but little protection to the 
antheridia, which at maturity often exceed their lobes in width. 
According to Stephani the perianth of A. sicaefolia is destitute of 
keels but the perianths he studied, according to his figure, were 
very immature. In mature perianths the five keels are sometimes 
apparent, but are often difficult to demonstrate when the faces 
between them are roughened in the same way. 
The lanceolate acuminate lobes and the autoicous inflorescence, 
together with the small perigonial bracts, will at once serve to 
distinguish A. sicaefolia from the two preceding species. A closer 
relative is apparently the Brazilian Lejeunea (Colo-Lejeunea) 
liliputiana Spruce,* known to the writer from description only. 
This species, which is also autoicous, is even smaller than A. 
sicaefolia, the leaves being only 0.15 mm. long. It is characterized 
further by the obtuse lobes of its leaves and by its smooth perianth. 
THE GEMMAE OF COLOLEJEUNEA, LEPTOCOLEA, AND 
APHANOLEJEUNEA 
The remarkable discoid gemmae found in the genus Cyclole- 
jeunea were described by the writer several years ago.t Each one 
arises from a marginal cell of a leaf lobe, and the stalk cell from 
which it becomes separated at maturity is attached to its basal 
edge. The three genera treated in the present paper also develop 
discoid gemmae, but these differ primarily from the gemmae of 
Cyclolejeunea in being borne on the surface of the leaf lobes instead 
* Hep. Amaz. et And. 297. 1884. 
t Bull. Torrey Club 31: 205-210. pl. 9, 10. 1904. 
