193 
CHARJE AUSTRALES ET ANTARCTIC, or characters and observations 
on the CHARACE® of Australia and the Southern npolar regions ; 
by Dr. ALEXANDER BRAUN. 
Aquatic plants have been in general regarded as cosmopolites, which, 
unrestrained by the common limits of phytogeographical regions, are to 
be found with unchanged specific types in the most distant parts of the 
world. The following enumeration, however, by no means confirms 
this assumption, being confined to a series of quite peculiar species 
representing the family of Characee in Australia. 
bert Brown, in his Prodromus Flore Nove Hollandie, enumerates 
only two species of the family of Characee. I owe the knowledge of 
these, and a third not yet described New Holland species, to the kind 
communications of the celebrated author. In the year 1843, I pub- 
lished in the 17th volume of Linnea, the Characeous plants collected 
by M. Preiss, in New Holland, by which the number of species known 
to this country amounted to eight. The most considerable increase, 
however, to our knowledge of the Australian Characee is due to the 
liberality with which Sir W. J. Hooker has opened to me his rich collec- 
tions. Among other precious materials, I find there a most important 
series of Characee, collected on the Swan River by the indefatigable 
Mr. James Drummond ; as well as several Antarctic species collected by 
Dr. J. D. Hooker during the voyage of the Discovery Ships Hrebus and 
I have remarked, all these species are peculiar to these countries, and to | 
be found in no other part of the world. Only two of them have a near 
resemblance with species otherwise known, so that, by a less restricted 
definition of species, they might be regarded as varieties ;—namely, 
Nitella penicillata, from Van Diemen’s Land, which resembles much 
Nitella, are those from the Swan River. Although there have been 
found not less than ten species at that settlement, none of them shows 
the calcareous incrustation, characteristic of many of our European 
species, but all are smooth and pellucid, without any incrustation or 
VOL. I. 2c 
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