$16 Mr. Brown’s Observations on the 
a structure, it may be remarked, equally militates against M. Bexa- 
vois’ theory, whether we suppose the columella to have existed 
- atan earlier stage, in the usual form, or not. 
_ As to this organ being tubular, and discharging its contents by 
` aye top, it is neither consistent with what has been already ob- 
served, nor with the appearance of its remains in the ripe cap- 
sule: but admitting for a moment its tubular nature, there are 
certain Mosses in which no discharge could possibly take place 
in the way described; the column being elongated even to the 
apex of the operculum, to which it often continues to adhere, as 
in Buabaumia, and in the first of the two new v genera which 1 
now proceed to describe. | 
DAWSONIA. 
Peristomium penicillatum, ciliis numerosissimis capillaribus rectis | 
equalibus e capsule parietibus volue () ortis. 
Capsula hinc plana, indè convexa. - | dá 
Calyptra exterior e villis implexis, interior apice scabra. 
Muscus hinc arcté affinis Polytricho, quo cum foliis, floribus mas- 
culis, et calyptrá penitüs convenit; indè, aliquo. modo. Bux- 
baumiæ accedens, presertim figurá capsule, et structurá colu- 
melle. Peristomio autem ab omnibus diversissimus. | 
Dawsoxta POLYTA. ICHOIDES. 
Tas. XXIII. Be. 1. 
Patria. Nove Hollandiz ora orientalis, extra tropicum. 
Statıo. Ripe subumbrose rivulorum, ad os monta in 
vicinitate Portüs Jackson. — | 
Dzsc. Caspites laxi, amorphi. Radicule tenuissime, tomenti 
instar 
