ON THE HUON PINE, &c. 145 
increases in proceeding to the westward from the African con- 
tinent in the southern hemisphere; and in another point 
of view, Australia may be considered the centre of their de- 
- velopment, as they are not only most abundant there, but 
the forms of New Zealand on one side, and of Africa on 
the other, resemble more those of Australia than those 
of America, or one another. 
The Tasmanian species of Conifere, so far as is at present 
known, are peculiar to that island, and more local there 
than in any other part of the globe. If Pachylepis be re- 
garded as a subgenus only of Callitris, then this island has 
representatives of all the genera peculiar to the southern 
hemisphere, except Araucaria; besides possessing the only - 
two that are not common to two of the regions enumerated 
above. I have before considered Tasmania as part of the 
Australian region ; but if we go on to compare it with the 
vast country lying to the north, it will be found still more 
peculiar in its Coniferous vegetation, as a part of that tract, 
| than the latter as a whole was shown to be; for whilst Aus- 
tralia has only three of the genera, Tasmania has six. 
Although, in a measure, anticipating the “ Flora of Tas- 
mania’ for which ample materials are in my possession for 
= publication, under the authority of the British Government, 
I shall here offer a few remarks on the different species of 
: that island, before proceeding to describe the noblest of them 
_ all, the Dacrydium Franklinii, or Huon Pine. 
1. Cauuirris, Vent. 
This genus, which was divided by Mr. Brongniart into 
two, has been further modified by Spach, who separates 
from both the North African C. quadrivalvis, for which alone 
entenat’s name of Callitris is retained. The differences i 
between these are excellently displayed by Spach in the 
Suites à Buffon” (Hist. Nat. des Végét., v. 11, p. 345), 
though I should not attach the same importance to them 
as does that acute observer. The numerous scales of 
the Australian group are certainly a remarkable character. — 
