Tlic Loess of Natchez, Miss. — Shiinek. . 279 
THE LOESS OF NATCHEZ, MISS. 
By B. Shimek, Iowa City, Iowa. 
PLATES X-XVI. 
The loess of Natchez, jNIiss., and of the lower, Mississippi 
valley, besides presenting a specially interesting field to the 
student, is classic ground, for here loess was first recognized in 
America by Sir Charles Lyell, who visite 1 thi resjion in 1846. 
It has received much attention since that time, and has been 
reportefl upon successively by \\'ales*, Hilgardf- Chamberlin 
and Salisbury,? AIcGee,§ and Mabry,|| while its fossils have 
received some attention from Binney.^i 
AAHiile it was at first regarded as distinct from the loess of 
the upper Mississippi drainage, it is indistinguishable from 
it in its physical characters, — especially from that which mav be 
designated as Missouri river loess. There are certain pecu- 
liarities of the fossil fauna of the southern deposit which have 
alreadv received some notice, but for the most part the refer- 
ences- to them are vague and unsatisfactorv, and do not suffi- 
ciently set forth their significance. 
It was the writer's good fortune to visit Natchez (and also 
A'icksburg) in May and June, 1898. The visit was made 
chiefiy for the purpose of studying the fossils of the loess and 
comparing them with the modern molluscan fauna now in- 
hal)iting the same region. As a result of this investigation 
more than 4600 fossil shells were secured, and some additions 
were made to the collections of modern molluscs from Missis- 
sippi and adjacent states made In- the writer in previous years. 
The season, however, was verv unfavorable for collecting 
living snails because of the lon§--protracted drought which 
caused them to hide away. This probably accounts for the 
-comparatively small number ( less than 900 specimens ) of 
modern snails in the Natchez collection, of wiiich more than 
one-half lielong to a species (Suceiiiea grosTenorii) not re]ire- 
sented in the local loess. 
In all more than fifty exposures of loess were studied at 
Natchez, and several were examined at Vicksburg, where but 
*Wailes. First Missi.ssippi report. 18.54. 
iHilgard. E. W. — Agriculture and Geology of Mississippi, 1860. 
JChamberlin. T. C. and Salisbury, R. D.— Sixth An. Rep. U. S. Geol. 
SuiVev., 1885. 
SMcGee, W. J.— Twelfth An. Rop. U. S. Geol. Suryey., 1891. 
ilMabry, T. O.— Journal of Geology, vol. VI. 1898. 
ffBinney, W. G. — A Manual of American Land Shells, Appendix IX, 
1885, etc. 
