152 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 Säo Thomé is 
nearly a flat-bottomed one, having a 
maximum elevation of about 2.1 me- 
tres above the highest tides. At the 
points Е 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 ou 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. 
ANN 
Fig. 84. Section of the beach north 
of S&o Thomé. 
Fig. 85. Section in a gully south of São Thomé, 
Yellow calcareous soil with shell fragments. . +. + душа DE 
Light gray caleareous soil made of shell and coral mt боп 18 
Dark chocolate brown sand with shell fragments. Color shades off 
into the brownish gray beds below . . - куо о LO 
Light gray calcareous sand with many loose shells ©, A 
