FROM THE TERTIARY DEPOSITS OF TA8MANIA. 351 



between these points, or had they emigrated from some one central 

 spot? 



Dr. Duncan-, in reply, stated that it was only by the united inves- 

 tigations of all students of geology that the question could be in 

 any way settled. The belief in the recurrence of glacial epochs was 

 founded on some erroneous conclnsioas drawn from beds in England, 

 South Africa, and in India, which were related to local glacier action 

 or to volcanic agglomerates. The Miocene plants could not have 

 existed without sufficient light; and severe frost would have destroyed 

 them ; and therefore they could not have extended so far north under 

 conditions similar to the present. The Echinoderms did certainly 

 present a striking resemblance to those found in the Miocene beds 

 of Malta ; but there were still sufficient specific and generic differ- 

 ences to justify him in describing them as distinct. 



