'82 THE DAWN OF LIFE. 



by the formation of projecting patches of supplementary 

 skeleton, penetrated by beautif al systems of tubuli. These 

 groups of tubuli are in some places very regular, and have in 

 their axes cylinders of compact calcareous matter. Some 

 parts of the specimens present arrangements of this kind as 

 symmetrical as in any modern Foraminiferal shell. 



"3. That all except the very thinnest portions of the walls 

 of the chambers present traces, more or less distinct, of a 

 tubular structure. 



" 4. These facts place in more strong contrast the structure 

 of the regularly laminated species from Burgess, which do not 

 show tubuli, and that of the Grenville specimens, less regularly 

 laminated and tubulous throughout. I hesitated however to 

 regard these two as distinct species, in consequence of the 

 intermediate characters presented by specimens from the 

 Calumet, which are regularly laminated like those of Burgess, 

 and tubulous like those of Grenville. It is possible that in 

 the Burgess specimens, tubuli, originally present, have been 

 obliterated, and in organisms of this grade, more or less 

 altered by the processes of fossilisation, large series of speci- 

 mens should be compared before attempting to establish 

 specific distinctions." 



(B.) Original Description of the Specimens added by 



Dr. Carpenteu to the above — in a Letter, to 



Sir W. E. Logan. 



IJournal of Geological Society, February, 1865.] 



" The careful examination which I have made, in accordance 

 with the request you were good enough to convey to me from 

 Dr. Dawson and to second on your own part, with the struc- 

 ture of the very extraordinary fossil which you have brought 

 from the Laurentian rocks of Canada,"^ enables me most 



* The specimens submitted to Dr. Carpenter were taken from a 

 block of Eozoon rock, obtained in the Petite Nation seigniory, too 

 late to afford Dr. Dawson an opportunity of examination. They are 

 from the same horizon as the Grenville specimens. — W. E, L. 



