645 
proofs that the primeval cras were distinguished by a wide if not 
universal spread of the same genera and species of animals. 
We have yet to analyze the enormous tracts of Australia over which 
British influence extends, before we can be said to have gathered to- 
gether all the palzozoic data which are essential to a sound general 
classification. The travels of Cunningham, Mitchell, Grey, and others 
of our countrymen, permit us however to conclude that the ancient 
strata of these regions may eventually be worked into a classification 
approaching to our own. In that singular country, in which so large 
a portion of the existing terrestrial and marine fauna differ so essen- 
tially from those of every other region, it is curious to detect in 
the rocks: many fossil Corallines and Mollusks* closely analogous 
to the Silurian species of the British Isles, thus adding another 
proof to many we already possess, that the same climatological and 
physical conditions were very widely spread during the earlier ages 
of the earth. Slender as our information is as yet respecting the 
natural history of that wide and detached continent which British 
industry is reclaiming, we cannot but anticipate a rapid accession 
to our knowledge, now that some highly-gifted naturalists are esta- 
blished in it. Whilst I simply allude to Mr. W. MacLeayt and 
Captain Philip King, whose researches are directed to branches of 
science connected with our own, itis my duty to mention more spe- 
cially the Rey. W. B. Clarke, a member of this Society, who has pre- 
viously contributed to our Proceedings and Transactions, and who 
in his recent voyage to Australia has afforded us fresh evidence that 
his leisure hours will still be employed in geological pursuits. A 
short residence at the Cape of Good Hope enabled him to com- 
municate to us a memoir on the structure of that colony, which 
seems to confirm what we had previously learnt from Herschel and 
Smith concerning its northern limits, and leads us to conclude that 
rocks of the Silurian age constitute the chief sedimentary masses of 
the southern promontories, though often much altered by the intru- 
sion of igneous rocks. 
Having alluded to Australia, I cannot refrain from expressing 
my delight, that Captain Grey, whose sketches of his arduous jour- 
neys in the wildest portions of that land are already placed among 
our standard works of travels, and whose future researches are cer- 
tain to enrich our knowledge, should happily have been selected to 
J. Hall has since forwarded to me his memoir, entitled ‘Notes on the 
Geology of the Western States.’—Silliman’s Journal, vol. xlii. p. 51. 
* See Mitchell's Expedition into the interior of Eastern Australia, vol. i. 
chap. 1; vol. ii. chap. 15. 
; Although Trilobites so characteristic of the protozoic xra have not 
yet been detected, my friend Mr. MacLeay acquaints me that he has re- 
cently recognized the first fossil crustacean found in Australia, a macrourous 
decapode, which being discovered by Mr. Emery of the Beagle, has been 
brought home by that officer, and through Dr. Fitton has found its way into 
our museum. “This crustacean (writes Mr. MacLeay) is nearly allied to 
Thalassina, and is interesting as a specimen from being the first fossil 
crustacean, and I believe the only one yet found in New Hollana,”’ 
