C rt ) 
XX. Some Observations on the ee ademas wi Descriptiong of 
_ four British Species. By William Jackson Hooker, Esq., F.L.S. 
Read May 1, 1810. 
Tue genus upon which it is my intention here to offer a few 
observations, was originally established by. Ehrhart in the first 
number of his Beiträge, and there received the name it has always 
subsequently borne, in honour of his friend J. G. R. Andrez, an 
apothecary and able naturalist at Hanover. The only species 
with which Ehrhart was acquainted was the 4. alpina, a plant 
that had long been known among botanists, but had always pre- 
viously been joined to the Jungermannie, between which and the 
Musci. calyptrati it unquestionably forms the connecting link ; 
so that, though amid all the various changes and improvements 
which have of late years taken place in the system of Mosses, 
the genus Andrea has had the peculiar good fortune of remain- 
ing unaltered, yet a question has always arisen, how far it pro- 
perly belonged to the order of Mosses, or Hepatice; its habit 
being almost equally intermediate between both, and its cap- 
sule seeming to partake more of the nature of the latter than of 
the former. I shall briefly notice what has been done by those 
botanists who have made any alteration in the character of the 
genus, or in its place in the systematic order; and.then proceed 
to a description of the parts of fructification ; from which I trust, 
VOL. X. 3D that 
