126 
NEW AKPiANGKlVrKNI^ OF 
dracea, pallide fusca, snbrigida. Sporida minulissiniae, 
iiumerosae, fuscae, sphsericae, obsolete retlculatae. 
Char. Diff. Tlieca (juadrlvalvls ; valva apicihus oper- 
culo connexis. 
Fructification. The receptade may be said to be ses- 
sile, but is elongated so as to resemble a seta, overtopping 
the perichaetial leaves, until it sometimes readies the length 
of a line and a half: it is white, succulent, vasculose, and 
cylindrical ; the base swelling out into a small bulb, while 
the summit sustains the subturbinate apophysis of the theca. 
The calyptra is thin, pellucid, whitish, and loosely reticu- 
lated, adhering, when young, to the top of the receptacle, 
and then entirely inclosing the theca; it separates early, 
and is torn transversely in a very irregular manner, the 
upper portion, or true calyptra, being exceedingly fuga- 
cious. There is no seta^ the theca, or, more strictly speak> 
ing, its apophysis^ which is full of a pulpy substance, being 
seated on the receptacle. The theca is of a deep brown 
colour, cylindrical in its young state, ultimately sub- 
quadrangular, and splitting longitudinally into four equal 
valves, whose summits are always bound together by the 
persistent operculum. In dry weather, the operculum is 
drawn down by a tendency in the valves to become invo- 
lute, which causes them to be bent outwards, until they 
almost form a semicircle, and the theca becomes turban- 
shaped. The operculum is small, conical, and obtuse, either 
similar in colour to the theca, as in J. alpina and nivalis^ 
or whitish, as in the other two species. There is no peri- 
stome. The columella is cylindrical, nearly equal in length 
to the theca, pale-brown, and of a somewhat rigid texture. 
The sporules are minute, numerous, brown, spherical, and 
obscurely reticulated. 
