and Paleontology of Victoria. 199 
Harrisoni, M‘Coy), which I have named after the discoverer, as 
well as the Graptolites Ludensis. The Hemithyris diodonta(Dalm.) 
is as abundant in the Mayhill Sandstone of Victoria as in the 
corresponding English beds at Malvern; and the same ap- 
pearance of oblong smooth Pentamerus (P. australis, M‘Coy) 
marks this sandy base of the Upper Silurian in Victoria as in 
England and Wales and North America. 
CAMBRIAN PERIOD OF SEDGWICK, LOWER SILURIAN OF 
. MURCHISON. 
It is to this period that I have been able without hesitation 
to refer the whole of the slates containing gold-quartz veins or 
reefs in Victoria; and all the slates containing these gold-bear- 
ing veins are identical in age and character with those of North 
Wales, in which the Romans worked the gold-mines of Gogo- 
fau. 
Not only are the majority of the fossil Graptolites found in 
the Welsh Llandeilo Flags and in the corresponding Cumber- 
land and Scotch slates, also found in those beds in Victoria, but 
we have in these formations the most extraordinary proof of the 
unexpected fact which I announced on a former occasion, that 
there was in the Cambrian or Lower Silurian period a nearly 
complete specific uniformity of the marine fauna, not only over 
the whole northern hemisphere, but across the tropics, extending 
to this remote temperate latitude of the southern hemisphere. 
In the slates of the gold-fields the principal fossils are Grap- 
tolites; and, what is very extraordinary, I have identified speci- 
fically here nearly the whole of the series of remarkable com- 
pound Graptolites first made known from the similar slates of 
Canada by the researches of Professor Hall. Many of the spe- 
cies have not yet been recognized in any but the Canadian loca- 
lities in the northern hemisphere; and to find nearly the whole 
series here is most interesting, as their powers of locomotion 
could only be exercised in the short ovarian and free stage ; so 
that, except on the supposition of a uniform marine fauna at 
this earliest zoological period of the earth’s history, we could 
searcely account for their width of distribution, and still less so 
of the littoral or shallow-water Mollusca which accompany them 
in other beds. The Diplograpsus mucronatus (Hall), so common 
in the Utica Slates of New York, I find in equal abundance 
here in the slates of Bendigo or Sandhurst, and with it abun- 
dance of the D. quadrangularis (M‘Coy), completely identical 
with those I described many years ago from the slates of Dum- 
friesshire. The Diplograpsus pristis (His., sp.) also occurs in 
these same slates, mixed with the others as in Sweden, Bohemia, 
and Scotland; but in certain different sandy beds it covers the 
