282 THE AMERICAN MIDLAND NATURALIST. 
small pond near Knoxville, and at Wartburg on the Emory 
river. Yet it is abundant in the adjacent Cumberland river. 
Here again transportation by birds is the most plausible factor 
to invoke to account for its presence in the pond at Knoxville, 
inasmuch as it is absent from the main river. Finally with 
regard to Long Island shells, it is undoubtedly true that other 
species can be transported similarly, but it is possible that 
the chemical composition of the water has favored the species 
cited. 
Dartmouth College. 
BIBLIOGRAPHY. 
1. Smith, S., and Prime, Temple; “Report on Mollusca of Long Island, 
N. Y. and Its Dependencies.” Annals Lyceum Nat. Hist., N. Y. Vol. 9, 
May, 1870. 
2. Wheat, 8S. C. “List of Long Island Shells,” Brooklyn Conchol. 
Club Bulletin, Vol. I, No. 1, 1907. 
3. Ames. Nautilus 16, 1902. 
4. Rich, S. C. “An Aberrant Form of U. Complanatus.” Science, 
N. S. vol. XLII, 1905. 
5. Johnston, C. W. “Fauna of New England part-13 List of Mollusca. 
Boston Society of Natural History, 1915.” 
