subexcurrente instructa.” Again, Schwaegrichen describes
his P. crassinervium, “ folia crassa, rigida, nervo crasso, latis-
simo, ad apicem pertingente;” whereas Bruch and Schimper,
in describing their “ P. crassinervium, Schwaegr.,” merely say,
“ folia costa basi pallida evanescente superne validiore, foliique
limbum superantehence it is doubtful whether they describe
the same moss. In the absence of conclusive evidence to the
contrary, we think it safer to refer the name crassinervium to
the only species of the two possessing a character in strict accordance
with the meaning of the word. It is to be regretted
that the authors of the Bryologia Europcea have not attempted
to justify a contrary proceeding in citing the figures of
Schwaegrichen and of Nees and Hornschuch, so very different
from their own, and so sideration. unlike the moss now under conThe
Rev. M. J. Berkeley first detected this moss near
Wansford, in Northamptonshire, in Dec. 1827. Mr. Mitten
has recently observed it at Hurst Pier-point and other places
in Sussex. Our specimens were gathered by John Thornhill,
Esq., in fields on the coast of Durham, about halfway between
Sunderland and South Shields, in October and December
1840, forming olive-green patches from 1 to 4 inches in diameter.
When in a young state it is accompanied by confer-
void shoots, which disappear as the plant advances to maturity;
hence they have been overlooked in some former descriptions.
Such shoots indeed are common to all mosses in an early
stage of growth, but are more conspicuous in the P/iasca; and
some writers (v. Bridel, Br. Un. 1. 29) have strangely fancied
them to be a distinct vegetable, specially designed to fulfil the
office of nurse towards the infant Phascum.
The leaves of our moss are remarkable for their linear shape
and for the thick and well-defined nerve, projecting beyond
the pagina, which often terminates more suddenly on one side
than on the other, giving an irregular figure to the apex of
the leaf. This character is often more conspicuous than is
represented in our magnified figure. The reticulation of the
leaf consists of roundish areolae, smaller than those of P. ser-
ratum. Usually the leaves are coarsely toothed near the
apex, and sometimes from the middle upwards. Capsule
broadly elliptical or roundish, with an oblique point nearly
half its own length, almost sessile on the vaginule, which is
longer and narrower than in P. stenophyllum, t. 2829, which
the moss very nearly resembles in size. Seeds rather large,
mpaildei aaten.d pellucid, about 100 in each capsule. Calyptra diThis
moss differs from P. stenophyllum, its nearest British
ally, in its broader, linear, not tapering leaves, the strong and
distinctly projecting nerve, and truly dimidiate calyptra. The
capsule also is larger and more pointed. It is closely allied
to P. cohcerens, Hedw.; but that species has the leaves considerably
broader and more lanceolate.—W. W.