52 
NEW ARRANGEMENT OF 
and occasionally emarginate *. Now, it should be observed, 
that these teeth, which are acknowledged to arise from the 
interior of the theca, appear to be a continuation of the lin- 
ing; whereas, in all the WeissiiE, the teeth either spring 
from the surface of the stoma, or immediately from within ; 
and are formed at the same time with the theca itself ; but 
the supposed teeth being thus only formed by the splitting 
of the horizontal membrane which connects the lining of 
the theca with the summit of the columella (and which we 
have already remarked to be pecuharly strong in Gymno- 
sfomum), the plant should perhaps be retained among those 
destitute of a true peristome "f*. 
Dr Hooker has published a new and singular species of 
Gymnostomum in his exquisite Musci Exotici J, under 
the name of Capense, which Mr Brown conceives to form 
of itself a distinct genus, named by him Glyphocarpa \\. 
Unfortunately the latter has published no character ; but, 
whatever it be, it assuredly ought not to rest on the form 
or striae of the theca, as, by the same principle, G. Lappo- 
nicum might also be removed ; and Bartramia arcuata, on 
• By the plate in English Botany, the peristome is decidedly that of an 
Orthotrichum ; and indeed were the Muscologia Britannica and English Bo- 
tany description of actual teeth to be correct, we would feel rather inclined to 
constitute of this a new genus, and arrange it close to Cal^/mperis, in the 
Orthotrichoidece. 
•f Since the plates for this paper have been engraved, we have observed, 
in Gym. microstomum, a similar structure, the horizontal membrane, which 
is usually striated, being, by age, turned upwards into sixteen very obtuse 
teeth. May not, in a similar way, Weissia affinis of Hooker and Taylor's 
Muscologia, be merely Gymnostomum contcumf from which it does not other- 
wise differ ? 
$ Muse. Exot., vol. ii. t. 165. 
jl Linn. Trans, vol. xii. p, 575. 
