120 THE CANADIAN NATURALIST. [April 



Illustrating the Structure and Affinities of Eozoon Canadense. 



Of the figures here given, 1, 3, 6 a, 6 b, and 7, are selected from 

 two plates given by Dr. Carpenter to illustrate his paper ; while 2, 4, 

 and 5, are from the plates accompaning Dr. Dawson's description, and 

 are from drawings by Mr. Horace H. Smith, the artist of the Survey. 



The figures, with the exception of 7, are from transparent sections of 

 specimens in which the original shell was well preserved, and its 

 minutest cavities infiltrated with serpentine. Figure 7 is from a speci- 

 men from which the calcareous skeleton was removed by an acid, and 

 represents the internal casts of the tubes, as seen by reflected light. 



' Fig. 1. Vertical section of regularly stratified portion of Eozoon 

 showing the ordinarily continuous connection of the cham- 

 bers of each stratum ; magnified 10 diameters. 



2. Horizontal section of Eozoon from Grenville, magnified 25 



diameters ; a, systems of tubuli ; b, secondary chamber. 



3. Portions of two chambers of different layers, showing at a, a, 



the proper walls of their chambers ; at b, b, the intermediate 

 skeleton ; and at c, c, a stoloniferous passage : magnified 25 

 diameters. 



4. One of the systems of tubuli cut transversely; magnified 100 



diameters. 



5. Part of a system of tubuli cut transversely ; magnified 200 dia- 



meters. 



6. Portions of the proper wall of the chambers, showing its Num- 



muline tubulation, as seen at a in longitudinal, and at b in 

 transverse section; magnified 100 diameters. 



7. Cast of the interior of canal-system ; an entire group magni- 



fied 10 diameters. 



ON THE MINERALOGY OF EOZOON CANADENSE,* 



By T. Sterry Hunt, M.A., F.R.S. 



The remains of Eozoon Canadense, a Foraminiferal organism 

 recently discovered in the Laurentian limestones of Canada, pre- 

 sent an interesting subject of study, both to the mineralogist and 

 geologist. For a zoological description of this organic form the 

 reader is referred to the preceding descriptions by Dr. Dawson and 

 Dr. Carpenter. 



The details of structure have been preserved by the introduction 

 of certain mineral silicates, which have not only filled up the 



[* See preliminary notice, Silliman's Journal [2] xxxvii, 431. J 



