72 THE ROYAL SOCIETY OF CANADA 



the earth's surface in this region; volcanic effusions entirely ceased, 

 and purely abrasive products formed the bulk of the sediments; in 

 eastern Cape Breton the basal beds are conglomerate, but in New 

 Brunswick they are firmly cemented gray sandstones, the upper 

 beds of which gradually pass into sandy gray shales containing the 

 fauna discussed below. 



PROTOLENIAN ZONE. 



The fauna of this group has not been recognized in Cape Breton, 

 but its place is between the Etcheminian and the beds holding Paradox- 

 ides. The Brachiopoda show among the species with round valves dis- 

 tinct genera in different basins in which the fauna of this group has 

 been found. Thus in the St. John basin we have Tremotobolus insignis, 

 in that of the Kennebecasis valley Protosiphon Kempanum and in that 

 of the "Long reach" of the St. John river Botsfordia pulchra, each so 

 far as known peculiar to its own basin and the whole not more than 

 a dozen' miles apart. Of course it may be said that these shells prob- 

 ably belong to different assises of the zone, but the gray sandy shales 

 in which they are found are apparently essentially similar. The 

 entire independence of these types may be due to the rapid changes 

 through which the fauna was passing. 



The genus Acrothele serves to link this fauna with the Etche- 

 minian below and the Paradoxides above, and helps to show the 

 interdependence of the three faunas. 



The typical genus of this fauna, if it were not unquestionably 

 beneath Paradoxides stratigraphically, might be thought to belong 

 to the Upper Paradoxides fauna, on account of its resemblance to the 

 genus Anomocare, Angelin; it is probably an ancestral related type, 

 without the wide anterior border to the head shield which marks the 

 typical species of Anomocare of the Swedish Paradoxides beds. It is 

 probable that the pygidium is more freely ' developed in Protolenus 

 than in Anomocare, and the long eyelobe of the former genus is in 

 keeping with its early appearance in time. 



Perhaps the most striking forms of the Protolenus fauna are the 

 Ostracoda which are of large size, and appear scattered sparsely over 

 the surface of the layers; thus they do not seem to have had the 

 habit of swarming, so notable in the later animals of this class — but 

 led a comparatively independent life. Although most of the Ostracoda 

 of the Protolenus fauna are smooth the genus Hipponicharion was 

 notably tuberculated or ridged, thus resembling Beyrichia, which, 

 however, is not found further down than the upper part of the Para- 

 doxides zone. 



