(J. crenulata.) 
BRITISH JUNGERMANNI/E. 
them is tender, and composed of numerous cellules, which are readily distinguishable with 
the microscope. The color is a dull green, at the apices frequently purple. 
Leaves (f. 3) by no means closely placed in the barren shoots, but crowded and imbricated 
in the fertile ones; in the former they are considerably smallest; in t lie latter the upper 
ones, which are the largest of all, are nearly half a line in length in many instances, 
erect, gradually lessening as they recede from the calyx; the rest, on the contrary, become 
smaller in proportion as they approach the extremity, and are generally patent; all of 
them are of a nearly orbicular figure (the lesser ones sometimes inclining to ovate), 
concave, with the margins usually plane. Their texture is somewhat carnose; the 
cellules are small, roundish, except at. the margin, where they are of a much larger size, 
regularly quadrate, forming a curious and very conspicuous border, which is still more 
remarkable in a dry state, when it becomes a little recurved, and is distinguishable by 
that circumstance, and by a somewhat paler color, even with the naked eye. The extreme 
edge of each of the marginal cellules is often swollen, thus forming the segment of a 
circle, which, of course, gives the leaf a crenulated appearance; whence the name 
adopted by Dr. Smith. This is, however, by no means universally so, nor have I ever 
seen the leaf altogether so much crenulated as the figure in English Botany represents it 
to be. The border itself is not unfrequently very obscure in the younger leaves, and in 
none so evident as in those upon the fertile shoots. The color of the leaves is extremely 
variable. I possess specimens, gathered by Mr. Lvell, which are wholly green, but the 
most usual hue is a dull olive, with the extremities often, and the terminal leaves 
generally, altogether of a rather deep purple. 
The Perigonial leaves resemble the rest, except, that they are more crowded and their base is 
swollen for the reception of the anthers. They are situated in various parts, but most 
frequently about the middle of the stem. 
Perichtetiul leaves differ in no respect from the rest that are placed upon the fertile part 
of the stem. When the calyx is young they form a sort of cup around its base, and when 
that part has reached its full size, they are about half its length or more, and are closely 
appressed to each side of it. They sometimes appear to have their origin from the lower 
part of the calyx itself, but this is by no means constant: for the calyx and perichaetial 
leaves will often be found to have one common point of insertion, at the extremity of 
the stem. 
Male Fructification situated in the axillfe of the perigonial leaves, in clusters, consisting of 
two or three, or more, anthers, each of which is spherical and reticulated, and supported upon 
a short, whitish footstalk. 
Female Fructification terminal* upon the main stems. 
The Calyx (f. 5) is three-quarters of a line or more in length, of an obovate figure, 
laterally compressed, and furnished with four longitudinal angles, which, in the full- 
grown calyx, are prominent and acute, but in the younger state far less evident and 
obtuse; at which time, also, the whole calyx is more spherical, and may readily be 
* Unless, indeed, as may happen with almost every species of the genus, the production of a shoot immediately 
beneath should give it the appearance of being lateral. This seemingly lateral situation may be more readily 
distinguished from a truly lateral one, in consequence of the much larger calycine leaves, on the upper part of 
the main stem. 
