158 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



was found under circumstances that place it quite beyond any doubt 

 abcrut its belonging where it was found. 



The shells have the general aspect of the shells of the present coast, 

 but I am disposed to think this an altogether too off-hand way of deal- 

 ing with them. I am not at all sure that a careful study would not find 

 a considerable difference between the fossil fauna of the sand plain and 

 the existing off-shore fauna. 



Shells may be left over a plain by the seaward extension of the shores, 

 or by the elevation of the sea-bottom. Inasmuch as this plain stands 

 from one to three metres above the highest tides, and as it is not wind- 

 bedded but is made up of horizontally bedded clays and sands filled with 

 recent marine shells, we must admit a recent elevation of at least three 

 metres to account for it. 



At Victoria, Espirito Santo. — Hartt long ago spoke of the evidence 

 of elevation on the island of Marica, off the coast between Rio de Janeiro 

 and Cape Frio,^ at Saut' Anna, and at Victoria, Espirito Santo. In 

 1899 I visited Victoria again and examined some of the evidence he 

 found there. This evidence consists of a horizontal line of open-mouthed 

 pits or depressions only a few centimetres deep but yet perfectly well 

 defined, and about one metre above the highest tide-level. This line is 

 most clearly shown on the big exfoliated peak formerly called the Pao 

 d'Assucar, but now genei'ally known as the Penedo. The same sort of 

 a line shows at several other places in the vicinity, notably on a big 

 block about four hundred metres further down the river, but always at 

 the same level. Hartt thought this line " evidently worn by wave action 

 within comparatively recent times." I am not sure what made the line, 

 but I am confident that it is due to a change of water-level. The pits 

 are not such as are made by sea-urchins, and I found nowhere on these 

 rock-faces or elsewhere similar lines worn by waves. The only explana- 

 tion that seems to be satisfactory is that they have been formed since 

 the elevation of the coast by the weathering along a line of partial 

 decomposition brought about by the effect on the rock of organisms that 

 once grew along that line. 



I have examined the line of organic growth near mean tide and low 

 tide levels at many places along the Brazilian coast, and I am disposed 

 to think that the line of pits on the Victoria rock correspond with the 

 low tide line of seaweeds, barnacles, and Serpulae — the line where these 

 things seem best to thrive. There is no proof of this, however. It is 



^ Geology and physical geography, p. 36. 42, 71-72. 



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