EOZOON CAtfADENSE AT COTE ST. PIERRE. 67 



The sections seen in the artificial exposures may be tabulated as 

 follows, though from the highly inclined position of the beds and 

 the irregularity of the excavations, perfect accuracy was not at- 

 tainable : — 



Mr. Lowe's Excavation (order descending). 



1. Limestone with serpentine and entire specimens of Eozoon — 3 feet. 



2. Coarse crystalline limestone, with layers containing fragments of Eozoon — 



4 feet. 



3. Limestone with concretions and layers of serpentine, and a few specimens 



of Eozoon — several feet, to the bottom of the excavation. 



Fisher's Excavation (order descending). 



1. Laminated limestone with bands of serpentine — 6 feet. 



2. White laminated limestone traversed by small veins of chrysotile — 8 feet. 



3. Limestone with concretions and interrupted bands of serpentine and 



pyroxene, and fragments of Eozoon — 10 feet. (Crystals and layers of 

 dolomite occur in this and the preceding beds.) 



4. Limestone with large concretions of serpentine, and in one layer fine-grained 



variety of Eozoon (var. minor) — 20 feet. 



5. Limestone with serpentine and perfect specimens of Eozoon. (This pro- 



bably corresponds to Lowe's excavation) — 12 feet. 



6. Coarse-grained limestone and dolomite — several feet. 



(After a break of several yards) 



7. Limestone with masses of pyroxene and veins of chrysotile and some imper- 



fect Eozoon. 



(After a break of several yards) 



8. Coarse-grained diorite, resting on a thick band of gneiss. 



In front of Lowe's excavation, and apparently overlying the lime- 

 stone exposed in it, is a narrow ledge of fine-grained gneiss ; and 

 beyond this other and probably overlying limestone appears, holding 

 pyroxene and mica. The whole vertical thickness of the limestone 

 exposed can scarcely exceed 150 feet ; but this is probably only a 

 small part of the development of the band at this place. 



In the strike of the limestone to the south it appears to bend 

 abruptly, or to be thrown by a fault, to the south-east, the gneiss 

 and diorite coming forward into a line with it, and the limestone 

 appearing in a little bare knoll in front of these. On the surface of 

 this limestone were found some fine specimens of weathered Eozoon. 



I examined carefully the relation of the bedded serpentine and 

 the veins of chrysotile or fibrous serpentine to the limestone. The 

 compact serpentine is evidently an original part of the deposit, 

 occurring in layers and lenticular concretions. In some beds it 

 shows no indication of the structure of Eozoon ; but in others it fills 

 the cavities of the fossils, and there are many regular layers of 

 fragmental Eozoon of considerable thickness in which it fills the 

 cells, while in other layers interstratified with these the fossil is 

 associated with dolomite. I satisfied myself on this point not only 

 on the ground, but also by taking away large specimens represent- 

 ing several thin layers, and treating them with dilute acid so as to 

 being out the structure. The following is a section of such a speci- 

 men, 51 inches in vertical thickness, treated with acid and examined 

 with a lens : — 



f2 



