Bilal ke 
EVANS: REPORT ON THE HEPATICAE OF ALASKA 593 
walls of their elongated cells, and in the elongated cells with 
thickened walls which form a border along the antical margin. 
In P. oxyphylla the leaves are relatively narrower than in 
P. pachyloma, measuring about 21.6 mm. The antical margin 
is entire, the apex is usually cipped with a single acuminate tooth, 
although a second smaller tooth is sometimes present at the aatical 
base of the apical tooth, or the apex may even be subequally 
bispinose. The postical margin bears from fifteen to eighteen 
sharp teeth or cilia, which are crowded toward the base and more 
scattered toward the apex. 
In P. fragilis the leaves are always deflexed and _postically 
secund, and the basal leaf-cells are always distinctly elongated. 
When well developed the leaves measure about 1.7 mm. in length 
and 1.4 mm. in width, ratio of width to length thus being about 0.8- 
The antical leaf-margin is entire, the dilated postical margin bears 
from twelve to sixteen spinose teeth, and the apex is usually 
unequally bidentate, the larger tooth being longer than the postical 
teeth. In some cases there is only one apical tooth. The leaf- 
cells in P. fragilis measure about 204 in diameter at the apex, 
30X20 uw in the middle, and 50X20 u in the basal region. The 
trigones, separated from one another by narrow pits, are unusually 
well developed, making the cell-cavities distinctly stellate; 
coalescence between trigones is not infrequent. 
26. Plagiochila Fryei sp. nov. 
Ona dry tree base. Augustine Bay (579). A slight admixture 
of Metzgeria conjugata is present. 
- Yellowish or brownish green, not glossy, growing in compact 
tufts: stems mostly 2-3 cm. long and 0.15 mm. in diameter, rigid, 
ascending, mostly simple, rarely with an occasional branch, the 
branches all intercalary, obliquely spreading, similar to the stems: 
thizoids sparingly produced: leaves alternate, more or less im- 
bricated, spreading at an angle of 45 degrees or less, posiically 
secund and often deflexed in the outer part, more or less convex, 
orbicular-ovate to orbicular (exclusive of the decurrent portions), 
about 1.4 mm. long (when well developed) and 1.2-1.4 mm. wide, 
long-decurrent antically, less decurrent postically, the decurrent 
' portions narrow, line of attachment strongly arched; antical 
margin revolute to about the middle, outwardly curved (on ex- 
Planate leaves), entire to the middle or beyond, sometimes bearing 
