and Palaontology of Victoria. 199 



Harrisoni, M'Coy), which I have named after the discoverer, as 

 well as the Graptolites Ludensis. The Hemithyris diudonta (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 Pentumerus [P. austndis, IM/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, btit 

 we have in these formations the most extraordinary proof of the 

 unexpected fact which 1 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 hemisphei'c, 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 Graji- 

 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 unifonii marine fauna at 

 this earliest zoological period of the earth's history, we could 

 scarcely 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 inuci'onatus (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 tbe D. quadrmiyularis (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 dilferent sandy beds it covers the 



