INTRODUCTION. 



liii 



Lethsea Geognostica. Theil 1. Palseozoica. Textband, Lief. 1. 1880. 

 Dr. F. Roemer. 



" Eozoic and Paleozoic." A Letter by Dr. J. W. Dawson in 1880. 



< Nature/ August 26, 1880. 



It begins by ' ' protesting mildly against " some reviewer of 

 Roemer' s ' Lethsea Palseozoica/ for having ' ' stated with respect 

 to Eozoon Canadense " that the latter " accepts the verdict of 

 Mobius against its organic origin, and rejects it from the list of 

 palaeozoic fossils." Why Roemer should commit such a sin, is a 

 matter which Dr. Dawson declares himself " at aloss to understand. 

 As a writer on palaeozoic fossils, Roemer has nothing to do with 

 Eozoon [eozoonism is strangely unreasonable] . It belongs to a 

 great series of eozoic or archaean formations which precedes the 

 palseozoic, and which probably represents quite as long a period. 

 Little comparatively is known of the fossils of these oldest rocks ; 

 but what we do know of their Eozoon, Archceospherina, Spiral 

 Arenicolites, and Aspidella [this last, and probably the preceding 

 one, may be fossils ; but it has yet to be proved that they do 

 not belong to Dr. Dawson' s Acadian group, which he regards as 

 Cambrian] , and of their immense deposits of graphitized plants [?] , 

 is sufficient to assure us that the life of the eozoic period was 

 very different from that of the palseozoic ; Eozoon, whatever its 

 nature [which now seems to be doubtful] , is one of the most 

 characteristic of these eozoic fossils. It has been recognized 

 through a great vertical thickness of beds, and over so wide 

 areas that it is now equally characteristic of eozoic rocks in 

 Canada and Brazil, in Bavaria and in Scandinavia [Ceylon, Skye 

 (Jurassic), Aker, India, New Jersey, Warren and other counties 

 in Northern New York, Connemara (Lower Silurian), Reichen- 

 stein, and the Vosges contain metamorphosed rocks demon- 

 stratively eozoonal] . Further, it has obviously been connected 

 with the accumulation of some of the greatest limestones of the 

 eozoic time." The reader, by referring to A.D. 1876, will find 

 that Prof. J. Hall, who believes in "Eozoon" has argued for 

 its being & paleozoic fossil ; therefore why he has escaped being 



