84 Geological Survey of Canada. 



eral additional Upper Silurian forms ; and in divisions E and F 

 the prevailing forms are those of the Clinton group of the New 

 York geologists. Great palseontological interest attaches to these 

 rock*, in consequence - of the numerous new species contained in 

 them ; and in a geological point of view they are especially im- 

 portant as affording a regular succession of fossil iferous beds 

 connecting the Lower and the Upper Silurian in America into 

 one great system. In New York, and in other parts of Canada 

 beside that under notice, the continuity of Jie series is broken 

 by the intervention of the Oneida conglomerate and the Medina 

 sandstones, and even locally by unconformability. To Anticosti 

 the physical changes which led to the spreading out of great beds 

 of sand and pebbles at the close of the Lower Silurian did not 

 extend. In this favored spot therefore of the old Silurian world, 

 we have the records of the slow changes of organic life which 

 went on independently of the direct action of these physical 

 changes, including probably the introduction of many species 

 which were not able to extend themselves over the sandy bot- 

 toms which prevailed at the time under a great part of the ocean 

 then representing America. 



On the one hand these Anticosti formations point to the local 

 character of those physical changes which form breaks in the se- 

 ries of stratified deposits, as compared with the more general ex- 

 tension of animal life and its comparative permanence. On the 

 other hand, they show that, perhaps very gradually and slowly, the 

 extinction of some species and the introduction of others were 

 proceeding, even in this comparatively undisturbed locality. 

 Such facts still leave unsettled the great question, to what extent 

 these changes were determined by the plan of succession esta- 

 blished by the Creator in organic life, and to what extent by the 

 new conditions of existence established by the operations of his 

 physical laws. That both were in harmony we cannot doubt, 

 but their precise relations are only beginning to be elucidated by 

 the accumulation of new facts like those above referred to, and 

 by the careful examination of each form of life included in these, 

 transitional deposits, in connection with the evidences of physical 

 change which they afford. 



Among the new fossils from Anticosti, one of the most curious 

 is that already mentioned under the generic name Beatricea, pro- 

 posed by Mr. Billings, who describes two species, B. nodulosa and 

 undulata. They are rough cylindrical trunks, one specimen ob- 



