Carhonifcroiix EiitomoHtraca from Nora S.>ofia. 321 



well iiiarkecl a Hpi^'ics, iind so usc^ful us an iiitlicator of 

 the liower Cail(oiuferou.s iu disturbed districts. 



Pig. 6, X !i6. 



6. Cythere (Species), (Fij,'. 6.) Valves, apparently 

 representing two species, occur in the Horton sliales, but 

 have not been identified as yet with any known species. 



II.- COAL FORMATION. 



Small bivalve Entoniostraca are very abundant in some 

 carbonaceous shales and bituminous limestones at the 

 South Jo<^'<^nns, Chiganois Iliver, East Kiver of Tictou, 

 Glace Bay, Cape Breton, Sydney, C.B., Malxju, C.B., &c., 

 where they seem to bare swarmed in the lagoons of the 

 coal swamps, as Cyprids do in some modern ponds, but 

 the species do not seem to be numerous. Those noticed 

 in the pa})er in (question are the following : — 



• y 



Fig. 7, X 25. 



1. Carbonia fabulwa, Jones & Kirkby (Fig. 7.) This is 

 one of the most abundant .species at all the localities, and 

 sometimes covers the entire surfaces of layers of shale 



