284 THE CANADIAN NATURALIST. [Vol. viii. 



Upper Laurentian. Mr. Vennor's observations relate to a region 

 about eighty miles distant, on the west side of the Ottawa, and 

 remarkable for its rich deposits of apatite and graphite, though 

 afford ins; Eozoon only in a few places, and in these not precisely 

 in the same state of mineralization as at Petite Nation and Gren- 

 ville. In this region Mr. Veunor has worked out a series corres- 

 ponding in its main features with that ascertained by Logan, and 

 it now appears that in both series Eozoon is apparently confined 

 to one horizon, and that in this it is associated with the more 

 important deposits of graphite and apatite. It is true that in 

 the districts explored by Mr. Vennor there are some groups of 

 strata of uncertain age, and which may be upper Laurentian or 

 even Huronian ; but the main accordance above stated seems to 

 be certain. It would thus appear that Eozoon and those deposits 

 of graphite and apatite which are probably of organic origiu, are 

 characteristic of one great zone of the Lower Laurentian. 



(6) The abundant phosphates occurring in the Lower Lauren- 

 tian, and as already stated in irregularly stratified beds, and 

 associated with graphite and Eozoon, naturally raise the question 

 whether they are of organic accumulation. The apatite of the 

 Lower Laurentian has indeed as yet afforded no organic struc- 

 ture. Some light may however be thrown on its origin by the 

 analogy of later deposits of similar character; and I have endea- 

 vored, in a paper recently read before the Geological Society of 

 London, to show that the calcic phosphate contained in the 

 Cambrian and Silurian rocks of Canada presents in its mode of 

 occurrence points of similarity to that of the Laurentian ; while 

 the pi-evalence of low forms of life, as Lingidce, Trilobites and 

 Ilyolithes, having much calcic phosphates in their skeletons, in 

 the Primordial seas, and the consequent accumulation of beds 

 rich in phosphatic concretions and coprolites, points to the possi- 

 bility of similar conditions in the earlier Laurentian. I may 

 also here refer, as corroborative of this view, to the recently 

 published researches of Hicks and others on the Silurian Phos- 

 phates of Wales. 



(7.) The objections to the animal nature of Eozoon recently 

 promulgated by Otto Hahn, and which have been answered in 

 detail by Dr. Carpenter and myself, have directed attention anew 

 to the geological relations of serpentine ; and though I must 

 protest against the idea prevailing in some quarters, that there 

 is any necessary connection between this mineral and Eozoon, 



