NUMMULINIDA : — EOZOON CANADENSE. 517 



very earliest that were previously known to contain Organic Re- 

 mains ; and the determination of its real character may be regarded 

 as one of the most interesting results of Microscopic research. This 

 fossil, which has received the name Eozoon Canadense, is found in 

 beds of Serpentine Limestone that occur near the base of the Late- 

 rcntian Formation* of Canada, which has its parallel in Europe 

 in the Fundamental Grneiss of Bohemia and Bavaria, and in the 

 very earliest Stratified Rocks of Scandinavia and Scotland. These 

 beds are found in many parts to contain masses of considerable 

 size, but usually of indeterminate form, disposed after the manner 

 of an ancient Coral Reef, and consisting of alternating layers — 

 frequently numbering more than fifty — of Carbonate of Lime and 

 Serpentine (Silicate of Magnesia). The regularity of this alterna- 

 tion, and the fact that it presents itself also between other Calca- 

 reous and Siliceous minerals, having led to a suspicion that it had 

 its origin in Organic Structure, thin Sections of well-preserved 

 specimens were submitted to Microscopic examination by Dr. 

 Dawson of Montreal, who at once recognized its Foraminiferal 

 nature :+ the Calcareous layers presenting the characteristic ap- 

 pearances of true Shell, so disposed as to form an irregularly 

 chambered structure, and frequently traversed by systems of 

 ramifying Canals corresponding to those of Calcarina (§ 387) ; 

 whilst the Serpentinoxis or other Siliceous layers were regarded by 

 him as having been formed by the infiltration of Silicates in solution 

 into the cavities originally occupied by the Sarcode-body of the 

 Animal, — a process of whose occurrence at various Geological 

 periods, and also at the present time, abundant evidence has already 

 been adduced. Although this determination has been called in 

 question, on the ground that some resemblance to the supposed 

 Organic structure of Eozoon is presented by bodies of purely Mine- 

 ral origin, J yet, as it has not only been accepted by all those whose 

 knowledge of Foraminiferal structure gives weight to their judg- 

 ment, but has been fully confirmed by subsequent discoveries, § the 

 Author feels j ustified in here describing Eozoon as he believes it 

 to have existed when it originally extended itself as an Animal 



* This Lavrentian Formation was first identified as a regular series of 

 Stratified Rocks, underlying the equivalents not merely of the Silurian, 

 but also of the Upper and Lower Cambrian Systems of this country, by 

 Sir William Logan, the accomplished Director of the Geological Survey 

 of Canada. 



t This recognition was due, as Dr. Dawson has explicitly stated in 

 his original Memoir (" Quarterly Journal of the Geological Society," 

 Vol. xxi., p. 54), to his acquaintance not merely with the Author's pre- 

 vious Researches on the Minute Structure of the Foraminifera, but 

 with the special characters presented by Calcarina, as exhibited in thin 

 sections which had been transmitted to him by the Author. 



t See the Memoir of Profs. King and Rowney, in the " Quart. Journ. 

 of Geol. Soc.," Vol. xxii., p. 185. 



§ See Dr. Dawson's account of a specimen of Eozoon discovered in_ a 

 homogeneous Limestone, in " Quart. Journ. of Geol. Soc," Vol. xxiii., 

 p. 257. 



