914 The American Naturalist. [November, 
reaches a vertical height of twenty-five feet from the level of 
the river. 
By far the larger portion of the shell heaps is made up from 
the remains of fresh-water shell fish, while the bones of various 
edible animals, principally deer, alligator and turtle, and some- 
times of man, crushed, split and occasionally charred, are 
found in them, but in very unequal distribution. 
The stand-by of the aborigines was the Paludina georgiana, 
a fresh-water snail. (Note B). Among the shells of this class, 
sometimes composing a layer of itself, is found the Ampullaria 
depressa, a snail of great size. The Unio (mussel) at times forms 
a fair percentage in the heaps. The Glandina truncata, a land 
shell, is occasionally met with, while various marine shells ` 
from the coast are of not infrequent occurrence. 
Prof. Wyman has called attention to a certain difference in 
size in favor of the paludine and ampullariz of the sbell heaps 
over those found in the river and its tributary streams at the 
present day. To this matter the writer has devoted careful 
attention, and has succeeded in finding paludine and ampul- 
lariz in the shell heaps far larger than any modern shells of 
the same variety and greatly exceeding in size, so far as the 
ampullarie are concerned, the measurements given by Prof. 
Wyman of those from shell heaps. (Note C). As to paludine 
no statistics are furnished by him. 
Stratification in the shell heaps is of course a matter of 
accident. The aborigines doubtless made use of the species 
of shell fish for the time being the most abundant, and such 
layers are of necessity local and not traceable through the 
entire heap. The condition of the shells often varies greatly 
in different portions of the same mound. At times large 
quantities are found unbroken, without admixture of sand 
or loam, and so loosely thrown together that they can be liter- 
ally scooped from the hole; again other portions of mounds 
are met with where fragments of shell and sandy loam are 
found in such close connection that the aid of a pick is necessary 
to effect their removal. It is apparent therefore that some 
parts of the shell heaps grew up under the aborigines dwelling 
upon them, and were beaten down and made solid by the press- 
