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bulletin: museum of comparative zoology. 



through a low neck of land at an elevation of 1.2 metres above the 

 highest tides. Between Ponta d'Areia and this place there are many- 

 patches of shells along the shores, but they are usually so scattered as to 

 lead one to suspect them, of having been left there by human agencies. 



At the point marked C on the west side of the ridge a bed of shells ex- 

 tends along the coast at an elevation of from 1.2 to 1.5 metres above tide. 

 At D on the map the encroachment of the sea has exposed another bit 

 of the elevated beach. 



The materials of the old beach are here shells and corals and water- 

 worn pebbles of Tertiary rocks resting upon the upturned and eroded 



edges of Cretaceous shales and sand- 

 stones. Clays from the hills above 

 cover the deposit. The top of the 

 shell bed at this point is one metre 

 above the highest tides. 



The valley north of Sao Thome is 

 nearly a flat-bottomed one, having a 

 maximum elevation of about 2. 1 me- 

 tres above the highest tides. At the 

 points E a road crosses this valley and 

 descends a gentle slope to cross a small stream. The road on these 

 slopes cuts into a soft rock made of shells like those on the present 

 beach. All over the higher parts of this valley, where burrowing ani- 

 mals have made holes in the soil, fragments of shells have been brought 

 to the surface. 



Fig. bo. Section in a gully south of Sao Thome. 



Yellow calcareous soil with shell fragments l'-2' 



Light gray calcareous soil made of shell and coral fragments . . . 1^' 

 Dark chocolate brown sand with shell fragments. Color shades off 



into the brownish gray beds below 8"-16" 



Light gray calcareous sand with many loose shells l'-'2' 



