450 
NEW ARRANGEMENT O? 
dry, but mostly approximated, as it were, in pairs. Colu- 
mella, in the dry state, mostly exserted, straight, rigid, di- 
lated at the apex, obtusej or, from the rigidity of the oper- 
cular membrane, acute» Sporules grey, minute, globose, 
pellucid. 
DiFF. Char. Fruit-stalk term'mal Theca xvith an 
apophysis. Peristome simple^ of gemifiating teeth closely 
rejieoced when dry. Columella dilated at the apex. Calyptra 
even, entire at the base, fugacious. 
Veg. The stems vary much in length, and are generally 
simple, rather slender, sometimes succulent, always erect. 
The leaves are inserted on all sides, more or less numerous, 
vasculose, diaphanous, the reticulation extremely lax; in 
form they have a range from lanceolate-acuminate to broadly 
ovate: they are also serrated, or entire, usually acute, but 
in >S'. vascidosum obtuse : all are furnished with a single 
nerve, disappearing before it reaches the point. The peri- 
ehaetial leaves scarcely differ from the cauline ones, except 
in being somewhat more attenuated. 
Obs. We have already stated, in our observations on 
the present group, how nearly related are all the genera. 
contained in it. Nevertheless there are no mosses (the 
Orthotrichoidese alone excepted) which vary so much in the 
apparent configuration of the peristome, or rather, in the 
combinations of its primary parts, when in the dry state. 
When moist, on the contrary, there are no mosses, the pe- 
ristomes of which so remarkably resemble each other. In 
this state, all the teeth are united, as it were, into one mass, 
usually arched over the orifice of the theca, and divided 
longitudinally by a definite number of equidistant strise, 
by means of which, it is easy, in almost every instance, to, 
