188 The Botanical Gazette. [April, 
in the character of their leaf-margins; but the various forms 
may be at once distinguished from P. zxterrupta by their as- 
cending habit, and from all our other species by their rotund 
or broadly ovate leaves with rounded apex. The Jeavesmay — 
be distant or imbricated, nearly plane or strikingly convex, 
obliquely spreading or deflexed, and their margins are entire, 
subentire or denticulate; in fact, several of these variations — 
are often found on a single stem, the tendency in such a cast | 
being for the leaves to become more crowded and more 
toothed as the apex of the stem is approached. 
The American forms with entire or subentire leaves weft 
collected in New York. After comparing it with his Fumge 
mannia interrupta, he states that it is more nearly related to 
F. asplenioides, differing in its “constantly entire, obovate 
cuneate leaves with less reflexed dorsal margin.” Dumortiet 
does not enumerate it among his species of Plagiochila,* 7 
Lindenberg both describes and figures it under this genus, a 
is also admitted into the Synopsis Hepaticarum, where, 
although it is placed next to P. interrupta, it is said to differ 
from entire-leaved forms of P. aspleniotdes in the gibbosity 
of its leaves, no other difference being stated. In allt 
works on American hepaticology, P. porelloides finds 4 place 
and it has also been distributed in several exsiccate. _ 
As early as 1849, however, Spruce doubted the validity of 
this species. In his valuable notes on the ‘‘Musci and ! 
tice of the Pyrenees,” he writes, ‘I have seen no specimet 
oides,”10 Forty years afterwards Lindberg?? reduced P. 
point of distinction which he gives is in the shape of tbe 
oe in P. porelloides this is stated to be “ovate-rectang™ 
* 1: 169. 1833. 
my gen Be 1835. 
- and Mag. Nat. Hist. . 
"1 Kongl. Sv. Vet. Ak. Hand. £8: 3475555 . 
