70 



DE. H. r. STANDING ON SUBFOSSIL 



Text-fig. 8. 



Channel through barrier of travertin separating fossil deposits from river. 



Turning, finally, to the question of the age of these deposits at Ampasambazimba, we 

 find that the data for the solution of the problem, while fairly numerous, are not very 

 precise. These data may be briefly enumerated as follows : — 



(a) The age of the neighbouring lava-flow as judged by disintegration of surface; 



(b) The depth of material worn through by the river in cutting its new channel ; 



(c) The depth of alluvial deposit in the marsh ; 

 (r?) The state of preservation of the fossils ; 



(e) The traces in the deposits of contemporary human occupation of the district ; 

 (/) Traditions of the natives as to the former existence of animals now extinct. 



The full discussion of these various points, while of much interest, would lead us 

 beyond the limits of this paper. A brief reference to a few salient facts must suffice. 



