CONTEMPORAKIES AND SUCCESSOKS OF EOZOON. 155 



structure is further complicated by the formation of 

 thin transverse plates, irregular in distribution, and 

 where greater strength is required a calcareous thick- 

 ening is added, which in some places shows a canal 

 system like that of Eozoon (fig. 41, B, c).* As com- 

 pared with Eozoon, the fossils want its fine perforated 

 wall, but have a more regular plan of growth. There 

 are fragments in the Eozoon limestones which may 

 have belonged to structures like these ; and when we 

 know more of the deep sea of the Primordial, we may 

 recover true species of Eozoon from it, or may find 

 forms intermediate between it and Archaeocyathus. 

 In the meantime I know no nearer bond of connection 

 between Eozoon and the Primordial age than that 

 furnished by the ancient cup Zoophytes of Labra- 

 dor, though I have searched very carefully in the 

 fossiliferous conglomerates of Cambrian age on the 

 Lower St. Lawrence, which contain rocks of all the 

 formations from the, Laurentian upwards, often with 

 characteristic fossils. I have also made sections of 

 many of the fossiliferous pebbles in these conglo- 

 merates without finding any certain remains of such 

 organisms, though the fragments of the crusts of some 

 of the Primordial trib elites, when their tubuli are in- 

 filtrated with dark carbonaceous matter, are so like 

 the supplemental skeleton of Eozoon, that but for 



* On the whole these curious fossils, if regarded as Fora- 

 minifera, are most nearly allied to the Orbitolites and Dacty- 

 loporas of the Early Tertiary period, as described by Car- 

 penter. 



