BRITISH JUNGERMANNIAS. 
(J. 
calyptrifolia.J 
Periclicetial leaves (f. 9) varying in number from two to four; erect, closely appressed 
to tire sides of the calyx, of which they are about one-fourth of the length, nearly 
quadrate, their sides incurved, their apex obtusely and widely emarginate. 
Stipules (f. 6) small, oblong, plane, appressed to the stem, or a little patent, divided 
for about one-third of their length from the extremity, by an acute sinus, into two 
equal, strait, and acute segments. 
Male Fructification unknown. 
Female Fructification lateral. 
Calyx (f. 8) large in proportion to the size of the plant, oblong, attenuated at the 
base, widening towards the extremity, where there are five projecting patent angles 
or teeth, which are very decurrent, extending sometimes one-third, and sometimes 
even more, of the length of the calyx: its extremity is depressed, and even flattened} 
the mouth much contracted, and a little jagged. In color and texture the calyx exactly 
resembles the leaves. 
Calyptra (f. f. 10. 11) spherical, narrowed and attenuated at the base, strongly reticulated, 
tipped with a tubular style. 
Peduncle about twice the length of the capsule, divided by transverse septa into a number 
of joints, each of which is composed of many minute capillary tubes; thus giving 
the peduncle an appearance which is observable in those marine Conferva which 
Mr. Dillwyn has called “ longitudinaliter venosa,” and, in which, he says, “ the filament 
is an aggregation of several smaller tubes*”. 
Capsule exactly spherical, white, membranous, pellucid, reticulated, dividing, for half 
its length only, into four equal, erect, conical segments, which support at their 
extremities the 
Spiral filaments, in the form of a small tuft or pencil; they are few in number, each 
appears (for I have not been able in the dry specimens to satisfy myself on this 
point so well as I could wish) to be formed of a double helix, and is enveloped in 
a thin, pellucid, membranous tube, open and a little expanded at the mouth. The 
seeds are large, of an oblong figure, here and there obtusely angular, of a dark 
green color. 
Gemma (f. 7) appear to be not uncommon, and are produced upon various parts of the 
stem, whence they readily separate, and upon the table of the microscope are seen 
floating about in the water, almost the instant the plant is immersed: they are larger 
than the seeds above described, nearly orbicular, depressed, composed of a few large' 
cellules: the color is pale green. 
J. calyptrifolia is one of the most curious species, and the most unlike every other in the Genus, 
that have been discovered by the two often-mentioned botanists, Miss Hutchins and Mr. Lyell. 
Hitherto it has always been found growing along with J. hamatifolia; but though so evidently 
* Dillw. British Conferva, p. 8. and 80. 
