316 THE CANADIAN NATURALIST. [Jan. 



but I think it on the whole more likely that they are casts of 

 cavities and tubes belonging to some calcareous Foraminiferal 

 organism which has disappeared. Similar bodies, found in the 

 limestone of Bavaria, have been described by Giimbel, who inter- 

 prets them in the same way.* They may also be compared with 

 the silicious bodies mentioned in a former paper as occurring in 

 the Logan ite filling the chambers of specimens of Eozoon from 

 Burgess. 



III. SPECIMENS FROM MADOC. 



I have already referred to fragments of Eozoon occurring in 

 the limestone at Madoc, one of which, found several years ago, I 

 did not then venture to describe as a fossil. It projected from 

 the surface of the limestone ? being composed of a yellowish dolomite, 

 and looking like a fragment of a thick shell. When sliced, it 

 presents interiorly a crystalline dolomite, limited and separated 

 from the enclosing rock by a thin wall having a granular or porous 

 structure and excavated into rounded recesses in the manner of 

 Eozoon. It lies obliquely to the bedding, and evidently represents 

 a hollow flattened calcareous wall filled by infiltration. The lime- 

 stone which afforded this form was near the beds holding the 

 worm-burrows described in the Society's Journal for November, 

 1866. 



[A thin section of this body, carefully examined microscopically, 

 presents numerous and very characteristic examples of the canal, 

 system of Eozoon, exhibiting both the large widely branching 

 systems of canals and the smaller and more penicillate tufts (PI. 

 III. figs. 4, 5) shown in the most perfect of the serpentinous 

 specimens — but with this difference, that the canals, being filled 

 with a material either identical with or very similar to that of the 

 substance in which they are excavated, are so transparent as only 

 to be brought into view by careful management of the light. 

 — W. B. C] 



IV. OBJECTIONS TO THE ORGANIC NATURE OF EOZOON. 



The discovery of the specimen from Tudor, above described, 

 may appear to render unnecessary any reference to the elaborate 

 attempt made by Profs. King and Rowney to explain the struc- 

 tures of Eozoon by a comparison with the forms of fibrous and 



* Proceedings of Eoyal Academy of Munich, 1866 ; Q. J. G. S. vol. 

 xxii. pt. i. p. 185 et seq. ; also, Can. ^Naturalist, vol. iii. p. 81. 

 t Quart. Journ. Geol. Soc. vol. xxii. pt. ii. p. 23. 



