286 TlIE GEOLOGISl'. 



Fishes. 



Auchonaspis Salteri, Eg. G. J. 13. Plectrodus mirabili?, Ag. S. S. GOG 



286, 704. 

 Ccphalaspis Murcliisoni, Eg. (x. J. 13. pustuliferus, Ag. S. S. G05. 

 284. ^ Ptercaspis Banksii, Iluxlcy and Salter 



ornatns, Eg. G. J. 13. 285. Geel. Jour. 12. p. 100. 



Onchus lAIurchisoni, Ag. S. S. GOT. 703. truncatus, id. G. J. 12. p. 100. 

 tenuistriatus, Ag. S. S. 607. 703. Spliagodus, Ag. S. S. G06. 



(Shagreen of Onchus? Thelodus 

 Ag. fide Salter). 



Localities of Tilestones and associated Rods. — Kington, Ludford, near 

 Ludlow, Eradnor Hill, Old Eadnor, Hagley Park, Downton Castle, Tin 

 Mill, Erockhill and Hales End, near Malvern, Hole Earm, Abberley, 

 Terton, near Stoke Edith, "Woolhope district, east of Llangadock. 

 Lesmahago, Lanarksliire. 



{To he continued.) 



THE COMMON FOSSILS OF THE BEITISH EOCKS. 

 By S. J. Mackie, Esq., E.G.S., E.S.A., &c., &c. 



CHAPTER III. 



TU Remnards Dftlie First Life world and the Bottom Rocks. 



(Continued from page 241.) 



The divisional line of the Bottom Eocks" is not, however, to be 

 placed at the point at which life first appears. This great series is 

 naturally divided by differences of mineral conditions, by order of 

 deposition, and in reality of age, in our own country, and in other 

 countries both of Europe and America, and apparently also, as far as 

 our present information goes, in Asia and Africa. 



In Canada, below the equivalents of our Shropshire " Bottom Eocks" 

 and of our lower Cambrian beds, as in the Highlands of Scotland, as wc 

 have already obtained, are still more ancient beds of sedimentary origin, 

 which have become crystalline. In Bohemia, in Finland, and in Scan- 

 dinavia we have these primeval gneissic lands below the lowermost 

 Silurian deposits ; but the geologists generally of other countries, except 

 the Canadian, have not yet made much progress in this investigation, 

 and it is only in very few instances that the distinctions between the 

 older and younger gneiss have been noticed ; and so little regard as to 

 gcologic[J age has been ordinarily paid in the case of granitic rocks, 

 tbat, Ivnowing as we do the very various periods at which some of those 



