150 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



for high water reaches only slightly above its base — indicates that the 

 shore has been raised at this point to a height nearly equaling that of 

 the cliff. What gives an increased interest to this locality is the pres- 

 ence of a low kitchen-midden, only two or three feet thick, which over- 

 lies the entire cliff. It is composed of a dark-colored, sandy earth, 

 packed full of the shells of the edible mollusks of the bay, with a few 

 scattered bones, and occasionally a human skeleton." 



When I was at Bahia in August, 1899, Mr. Joseph Mawson directed 

 my attention to important evidence of elevation north of Sao Thomd on 

 the bay of Bahia, and on the trip to and from that place I was able to 

 collect many other bits of evidence pointing to an elevation of the coast.-' 



The accompanying sketch-map of the region, made on the spot, will 

 serve, in the absence of a better one, to show the topographic relations of 

 the points mentioned. It should be remembered, though, that both the 

 orientation and the distances on this map are only approximately correct. 



With the exception of the late beds with which we are especially con- 

 cerned, the rocks of the region are all folded, faulted, and sometimes 

 decomposed Tertiary sediments. 



At the Ponta d'Areia, a point marked A on the northwest corner of the 

 map, there is a flat bit of ground, not more than four acres in area. 

 Half of this flat ground has a sloping sandy beach, and the remainder, 

 in the northeast corner, has a low natural rock wall about 100 to 150 

 metres long for a water front. This rock lies in horizontal beds, and is 

 made up of shells, corals, and comminuted calcareous matter of various 

 degrees of hardness. The total thickness of the beds could not be seen 

 at the time the place was visited, on account of the tides, but they ex- 

 tend from below high water to about one and a half to two metres above 

 the highest spring tides. The uppermost metre of this is soft sand 

 merging into hard rock below. The surface itself is very black soil to a 

 depth of from fifteen to twenty centimetres, and I suspect it of having a 

 human origin. The material of the lowest part of the beds is of very 

 much ground-up shells and corals. 



It is possible that the shells on this point rise to a height of three 

 metres above tide, but those seen on the highest grounds all belong to 

 species that are used for food even to this day, and it is doubtful whether 

 they ought to he included with the elevated beds. 



At the point marked B on the map marine shells are strung along 



1 I am also under obligations to Mr. Richard Tiplady, Superintendent of the 

 Estrada de Ferro da Bahia ao Suo Francisco, and to Mr. Thomas Mawson, of the 

 same road, for facilitating in every possible way my visit to this interesting region. 



