608 Evans: REPORT ON THE HEPATICAE OF ALASKA 
thin but with small trigones having concave sides, cuticle smooth: 
leaves of primary branches more or less imbricated, the lobe convex, 
more obliquely spreading than in the stem-leaves, ovate, about 
0.45 X0.35 mm.; the lobule trapezoidal in outline, the free margin 
being shorter than the keel, about 0.3 X0.2 mm.: leaves of second- 
ary branches still more obliquely spreading, subequally bilobed, 
the lobes about 0.18 X0.1 mm.: inflorescence unknown. (TEXT 
FIGS. 2, 3.) 
Fics. 2,3. Radula polyclada Evans. Fic. 2. Part of a stem showing seven 
branches, postical view, X 25. Fic. 3. Cells from the middle of a lobe, X 339- 
The figures were both drawn from the type specimen. 
The numerous branches with their limited growth give the 
shoots of R. polyclada a distinctly plumose appearance, so that 
they bear a certain resemblance to the secondary shoots found in 
Porella and in the tropical genus Bryopteris. They look in fact 
as if they also might be secondary shoots arising from a prostrate 
