PORELLA : 165 
the river Bober, near Hirschberg, Silesia, and upon European 
specimens and the descriptions of authors. : 
The name dentata, applied by Hartman in 1832 (Skand. КІ. 
354, 2d ed.) to what he considered a variety of Jungermannia 
platyphylla was taken up for the above species by Lindberg in 
1869, but was abandoned by him ten years later without explana- 
tions. Hartman’s description of his variety dentata is quite inade- 
quate for its proper identification and as we have failed in our 
efforts to see his original specimens, if such exist, we prefer to ad- 
here to the first name which was accompanied by an intelligible 
diagnosis. 
3. PonELLA Кок Steph. Bot. Centralb. 45: 203. 1891. 
liquely ovate, patent-divergent, .85-1.7 mm. x .65-1.5 mm., apex 
narrowed, subtruncate, obtuse, or most rarely apiculate, inferior 
margin more or less undulate-crisped, the superior repand, cells at 
basal angles slightly smaller, all with evident trigones; ventral 
lobes ovate, linguiform or ovate-oblong, usually much narrowed 
toward the obtuse or subacute apex, suberect or patent, scarcely 
connate with the dorsal, commonly about 14 as wide as the un- 
derleaves, length 24 the width of the dorsal, somewhat concave 
rarely subciliate: underleaves approximate, ovate-linguiform, 
rounded-obtuse, the margins recurved, long-decurrent, entiré or 
most rarely subdentate, the wings sometimes crisped: dioicous : 
7 spikes 1-2 mm. long: $ branch somewhat elongated, bearing 
3-8 leaves (or “ bracts”) (usually 2 pairs) nearly similar to the 
cauline ; inmost bracts a little larger, the lobes subacute, entire, 
repand-dentate, or sparingly denticulate, bracteole ovate, subentire 
or denticulate ; perianth large, somewhat goblet-shaped or broadly 
obovate, undulate-concave ventrally, here and there inflated, 
the oral margins plane or slightly deflexed at the sides. 
Under shelving rocks and on moist shaded cliffs, rarely on 
tree-trunks. Mill Valley (1168) and Mt. Tamalpais (1171), Marin 
