Cavibrian Rocks in Cajse Breton. 437 



OSTEACODA OF THE BaSAL CaMBRIAN RoCKS IN CaPE BrETON 

 By G. F. Matthew, LL. D., F.R.S.C. 



Investigations of the Cambrian rocks in Cape Breton 

 has brought to the writer's notice a number of new types 

 of these small Eutomostracans, and with the permission of 

 the Director of the Canadian Geological Survey, these are 

 communicated to the Natural History Society of Montreal. 



The species all come from the Etcheminian sandstones 

 and shales, and from a body of shales included in the 

 volcanic rocks which underlie them. This part of the 

 Cambrian appears to- contain three faunas, one in the 

 shales of the volcanic rocks, and two in the Etcheminian 

 sediments. , 



Only two species of Ostracoda have been found in the 

 shales of the volcanic rocks, so that the bulk of the fauna 

 is Etcheminian. The distribution of the forms throughout 

 this series of beds will be readily seen by the accompany- 

 ing table. The three larger divisions of the Etcheminian 

 shown in the table are lithological, and the Lower Etche- 

 minian Fauna is confined to the two lower divisions ; the 

 Upper Eauna is in N"o. 3, the upper division. The letters 

 beneath these divisional spaces indicate the successive 

 assises in which fossils have been found. ]^o Ostracoda of 

 the Protolenus Zone have been recognized in these beds, 

 and so it is supposed they are older than that fauna. 



