TRANSACTIONS OF SECTION C. 711 



of instances it has been assumed that similarity between fossil terrestrial faunas 

 and floras proves identity of geological age, and, by arguing in a vicious circle, the 

 occurrence of similar types, assumed without sufficient proof to belong to the same 

 geological period, has been alleged as evidence of the existence of similar forms 

 in distant countries at the same time. 



In the preceding remarks it may perhaps have surprised some of my auditory 

 that I have scarcely alluded to any American formations, and especially that I have 

 not mentioned so well known and interesting a case of conflicting palasontological 

 evidence as that of the Laramie group. My reason is simply that there are 

 probably many here who are personally acquainted with the geology of the 

 American Cretaceous and Tertiary beds, and who are far better able to judge than 

 I am of the evidence as a whole. To all who are studying such questions in 

 America I think it will be more useful to give the details of similar geological 

 puzzles from the Eastern hemisphere than to attempt an imperfect analysis of 

 difficult problems in the great Western continent. 



Perhaps it may be useful, considering the length to which this address has 

 extended, to recapitulate the principal facts I have endeavoured to bring before 

 you. These are — 



1. That the geological age assigned on homotaxial grounds to the Pikermi and 

 Siwalik mammalian faunas is inconsistent with the evidence afforded by the 

 associated marine deposits. 



2. The age similarly assigned on the same data to the different series of the 

 Gondwana system of India is a mass of contradictions ; beds with a Triassic fauna 

 overlying others with Rhsetic or Jurassic floras. 



3. The geological position assigned on similar evidence to certain Australian 

 beds is equally contradictory, a Jurassic flora being of the same age as a 

 Carboniferous marine fauna. 



4. The same is probably the case with the terrestrial. and fresh-water faunas and 

 floras of South Africa. 



6. In instances of conflicting evidence between terrestrial or fresh-water 

 faunas and floras on one side, and marine faunas on the other, the geological age 

 indicated by the latter is probably correct, because the contradictions which prevail 

 between the evidence afforded by successive terrestrial and fresh-water beds are 

 unknown in marine deposits, because the succession of terrestrial animals and 

 plants in time has been different from the succession of marine life, and because in 

 all past times the differences between the faunas and floras of distant lands have 

 probably been, as they now are, vastly greater than the differences between the 

 animals and plants inhabiting the different seas and oceans. 



6. The geological age attributed to fossil terrestrial faunas and floras in distant 

 countries on account of the relations of such faunas and floras to those found in 

 European beds has proved erroneous in so large a number of cases that no similar 

 determinations should be accepted unless accompanied by evidence from marine 

 beds. It is probable in many cases — perhaps in the majority— where the age 

 of beds has been determined solely by the comparison of land or fresh-water 

 animals or plants with those found in distant parts of the globe, that such deter- 

 minations are incorrect. 



The following Papers were read : — 



It Results of past experience in Gold Mining in Nova Scotia. 

 By Edwin Gilpin, Jan., A.M., F.G.S., F.B.S.C. 



The gold fields of Nova Scotia stretch along the whole Atlantic coast of the 

 province, and occupy an area of about 7,000 square miles. 



The auriferous measures may be divided into two series, an upper one con- 

 sisting of black pyritous slates with occasional bed of quartzite and some auriferous 

 veins and a lower one made up of alternating beds of slates and quartzites and 

 compact sandstone, sometimes felspathic. The upper series is estimated to be 3,000 

 feet thick, the lower 9,000 feet. 





