116 ROYAL SOCIETY OF CANADA 



zone of the limestone near the contact with the gabbro mass, for the 

 extraction of asbestos (crysotile), a mineral occurring at a number 

 of places in the crystalline limestone of eastern Quebec as small threads 

 or veinlets. 



This serpentinized portion when present always occurs at or near 

 the base of the calcareous bands, and often is accompanied with a 

 development of the crysotile. Attempts to mine this mineral have 

 been frequently made near the igneous contacts, and it was evident, 

 on careful study of the conditions at a number of these openings, that 

 the alteration to serpentine and the development of the crysotile 

 veins was due to the action of the intrusive masses on the basal portion 

 of the limestone bands. The original contention therefore that these 

 forms known as Eozoon were of organic origin has practically ceased 

 to exist or to find supporters. 



As regards the peculiar forms found in the crystalline limestone 

 in the vicinity of St. John, which have been described under the name 

 Archseozoon, from several localities, the same intimate association 

 of igneous masses is frequently observed. In the report to the 

 Geological Survey, 1870-1, by Bailey and Matthew, they are referred to 

 as occurring in beds of limestone exposing " over a surface nearly 

 ten feet square, large numbers of concentric nodular masses, bearing 

 much resemblance to some genera of corals, but apparently destitute 

 of organic structure, and probably concretionary." From their pre- 

 sence, however, in limestone in which sponge spicules are found, they 

 may possibly belong to one of the lower orders of sponges, related to the 

 Archseocyathus of Newfoundland. They certainly bear but small re- 

 semblance, either in mode of occurrence or general aspect, to the form 

 known as Eozoon Canadense of Ontario or Quebec. A description 

 of this form was published by Dr. Matthew in Bull. No. IX, Nat. 

 Hist. Soc, N.B., 1890, in which its organic nature is maintained. 



In the same bulletin Dr. Matthew also pointed out that in the 

 so called upper Laurentian of southern New Brunswick, as found 

 about St. John, three zones were recognizable which contain fossil 

 forms. These were held to be separated from the then recognized 

 base of the Cambrian by the Huronian series. His statement as to 

 the occurrence of these fossils in these upper Laurentian rocks, as 

 there given, may be briefly summarized, in order to arrive, if possible, 

 at a clearer understanding of the problem of their structure, which 

 is now a matter of considerable geological importance. 



As already intimated, the rock formations of this series consist 

 of crystalline limestone, slate and quartzite with masses of intrusive 

 rocks. The sediments contain organic remains, of which the oldest 

 apparently is in the quartzite portion belonging to the lower part of 



