EOZOON 



837 



zone there seems to be no direct connection. They are brought into 

 relation, however, by means of annular canals, which seem to repre- 

 sent the spiral canals of the Nummulite, and of which the ' internal 

 casts ' are seen at b b, b' b', b" b". 



A most remarkable fossil, referable to the foraminiferal type, 

 was discovered in strata much older than the very earliest 

 that were previously known to contain organic remains ; 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 (fig. 640), is found 

 in beds of Serpentine limestone that occur near the base of the 



PIG. 640. Vertical section of Eozoon cn/tnJi ityc, showing alternation of 

 calcareous (light) and serpentinous (dark) lamellce. 



Laurentian formation of Canada, which has its parallel in Europe in 

 the ' fundamental gneiss' 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 from 50 to 100 of carbonate of lime and serpentine 

 (silicate of magnesia). The regularity of this alternation and the 

 fact that it presents itself also between other calcareous and silicious 

 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 the late Sir W. Dawson, of Montreal, 



