192 Evans: HEPATICAE OF PuERTO RICO 
is also strongly reflexed but bears a rudimentary lobule; the 
third and succeeding leaves are similar to ordinary leaves, gradu- 
ally increasing in size and acquiring normal lobules. The first 
underleaf is similar to that found at the base of an ordinary 
branch ; it is small and flat, oblong in outline without any indica- 
tion of basal auricles, and is entire on its margin; it apparently 
possesses no rhizoid-initials and is attached by a short straight line 
of insertion. The second underleaf is the most remarkable fea- 
ture of the propagulum and shows very striking modifications. It 
is orbicular in shape and is also entire on the margin, but the base 
is deeply and truly auriculate, the region of insertion being short 
and at about the middle of the underleaf. The axis-cells, by 
which the attachment is effected, become elongated and push the 
underleaf away from the axis, forming as it were a kind of stalk 
(FIGURE 15). At the top of this stalk the disc is developed and 
eventually becomes larger than the underleaf itself. The disc 
consists of two layers of cells, those in the middle being at first 
small and polygonal in outline and forming a patch about six 
cells across. The marginal cells, which are really rhizoids, are 
likewise in two layers and very soon become long and narrow, 
radiating out in all directions. Instead of remaining distinct, as 
rhizoids commonly do, they are united except at their tips and 
thus form, around the middle of the disc, a broad and continuous 
border crenulated on the edge (FicuRE 14). These rhizoids pos- 
sess ina marked degree the property of secreting slime. After a 
propagulum has established itself, the middle cells of the disc may 
also develop rhizoids. The third and succeeding underleaves of 
the propagulum are similar to ordinary underleaves and develop 
radicelliferous discs of the usual type. 
CYCLOLEJEUNEA 
The genus Cyclolejeunea as here understood has four represen- 
tatives in Puerto Rico. The first of these, C. Chitonia, is known 
from British Guiana and from several of the Lesser Antilles ; the 
second and third, C. convexistipa and C. accedens, have already 
been listed from the island * and have a wide distribution in South 
America; the fourth, C. angulisti~a, is apparently restricted to 
* Hedwigia, 27: 281, 284. 1888, 
