148 
^CEW ARUAKGEMENT OF 
tion of the theca an Operculum. This is not the result of 
caprice ; for it will be found that the oblique attenuated 
point is destitute of sporulas, and that the sporular bag 
actually terminates at the summit of the ovate portion of 
the theea, to which, therefore, the term Theca can only be 
applied. The more pellucid appearance in the acuminated 
summit, as observed by Hornschuch, was owing to this 
absence of sporulse ; we therefore consider it as a true oper- 
culum. He adds also, that it is of a different texture, — 
" texturae laxioris." We shall close these observations with 
another remark from that learned Professor, but which we 
ourselves have not been able completely to verify; viz. 
that the vaginula^ in this genus, is composed of two valves. 
In all mosses, at an early period, the vaginula and calypti'a 
are otle and the same ; the latter is, by the enlargement of 
the theca, torn from the lower portion, and each part 
then receives a distinct name, and becomes independ- 
ent of the other. In Andma and Sphagnum this is 
peculiarly visible ; the portion left at the base, now called 
Vaginula, is generally entire, and it is so in Phascum. On 
this character, the above mentioned commentator lays much 
stress in his diagnosis of the two genera ; but we do not see 
that it is of so much importance as the points we have al- 
ready enumerated. 
Hab. These plants have hitherto only been found on 
the summit of the Carinthian Alps and in Melville Island. 
We have not been able to ascertain whether those brought 
from the latter place grew upon the dung of animals, as 
was the case with those discovered by Dr Hornschuch: 
from our specimens we should rather imagine the contrary. 
Hist. Br Hornschuch Avas the first fortunate dis- 
coverer of this curious genus in 1817, a figure and descrip- 
