r899 C. CALLAWAY— ON EARLIEST LIFE 



77 



discovered a volcanic series below the Cambrian of 

 St. David's, and this he called " Pebidian." These rocks 

 have also been identified in Shropshire, the Malverns, 

 Charnwood Forest, and other ^Midland localities; but 

 here we name them " Uriconian," though I have always 

 conceded that Hicks' term has priority. More recently, a 

 third Archaean group has been established in Western 

 Shropshire. The vast series of slates, sandstones, and 

 conglomerates composing the hill range of the Longmynd, 

 originally identified by Alurchison and the Survey as 

 Lower Cambrian, underlies the lowest Cambrian uncon- 

 formably, and the present Director of the Geological Sur- 

 vey now admits its Pre-Cambrian age. I have called this 

 formation the Longmyndian. Rocks of probably the same 

 age have been found underlying the basal Cambrian of the 

 Scottish Highlands. In America, also, more than one 

 series of strata have been found to lie between the 

 Huronian and the Cambrian. The name "Algonkian" 

 has been given to the most prominent of these formations 

 in the United States. The rocks immediately under- 

 lying the Cambrian, on Lake Superior, are called " Kewee- 

 nawan." Whether these formations, or either of them, 

 were formed contemporaneously with our Longmyndian 

 it is impossible to determine on the present evidence ; but 

 in a general way we may regard them as occupying the 

 corresponding position in the geological series. 



It would not be difficult to speculate on the succession 

 of life in Archaean time; but I wish at present to confine 

 your attention to bare facts. Much has been written on 

 the life of the Laurentian (Malvcrnian) epoch. The 

 famous Eozoon (Dawn-animal) has done dutv in text 

 books as long as I can remember. It fitted so neatlv into 

 the evolutionary scheme that it seemed as if it must be 

 real. But regretfully we must come to the conclusion 

 that this supposed ancestor to all the forms of animal life 



