1919]  Evans,— Notes on New England Hepaticae,— XV 159 
the apex; while those of the surculi, arising from the ventral surface 
of the stems, are said to be half as large as the stem-leaves, ovate or 
obovate in form, scarcely decurrent, and markedly obtuse at the apex. 
Austin noted further that the uppermost rhizoids were sometimes red 
but made no mention of the male bracts. These were detected by 
Lindberg, who recognized an affinity between N. Ayalina and N. 
biformis, emphasizing the purple rhizoids, but who made no attempt 
to reduce the latter species to synonymy. 
An examination of Austin's specimens indicates that they represent 
an environmental modification. Possibly the development of the 
numerous surculi has been induced by water flooding the prostrate 
stems. These surculi are not especially distinctive, very similar 
branches being often present in tufts of typical N. hyalina, especially 
when the plants are crowded. Many of the leaves on the surculi are 
distinctly though shortly decurrent, and the differences between the 
two forms of leaves are often less marked than the original description 
implies. The leaf-cells, as Austin notes, are thin-walled, but some of 
them show minute trigones and the cuticle is often vaguely verruculose. 
The male bracts agree closely with those of N. hyalina. On the whole 
there seem to be no trustworthy characters for separating N. biformis 
as a distinct species. 
2. Nardia obscura sp. nov. Growing in more or less compact 
tufts, bright green varying to deep blackish purple: stems mostly 
1-2 em. long and 0.2-0.45 mm. in diameter, the older portions prostrate 
and closely adherent to the substratum, the younger portions usually 
free from the substratum, sparingly branched, the branches inter- 
calary, arising from the lateral segments just above the ventral leaf- 
bases, sometimes leafy but often in the form of slender stolons; no 
subfloral innovations observed; rhizoids usually abundant on the 
prostrate stems and stolons, rare elsewhere, colorless to deep purple, 
not forming a ventral bundle; leaves distant to loosely imbricated, 
slightly decurrent dorsally and sometimes ventrally, attached by 
oblique lines but usually appearing subtransversely inserted at the 
dorsal base, broadly ovate to orbicular, mostly 0.9 X 1.5 mm. long 
and 0.75-1.5 mm. wide, usually rounded at the apex but sometimes 
retuse, margin entire; leaf-cells thin-walled but with minute trigones, 
marginal cells not differentiated, mostly 15-20 u in diameter, median 
cells mostly 25-35 u long and 20-28 u wide, cuticle smooth to deli- 
cately striate-verruculose: underleaves lacking: inflorescence dioicous, 
the male and female plants sometimes in the same tuft: peri- 
chaetial bracts in about two pairs, a little broader and more undulate 
than the leaves but otherwise very similar; perigynium and perianth 
