344 The American Geologist. De.^mber, looi 
Lacoc Collection of Palaeozoic Fossils in the Wyoming Historical 
and Geological Society, VVilkesbarre, Pa. Printed from his carefully 
prepared manuscript. Proceedings of the Society, vol. V. 1900, pp. 
177-204. 
Reprint of same. 8vo, pp. iv + 26, 1900. 
THE LOESS OF IOWA CITY AND VICINITY.* 
By B. SiiiMHK, Iowa City, Io\Ya. 
The loess of Iowa Cit}- presents no unique features. It is of 
the t}pe which prevails in the eastern- part of the state, being 
fine and homogeneous ; found chiefly on highlands, especially in 
its imdisturbed condition, and following their vertical contours, 
thus varying but little in thickness which seldom exceeds 
twelve or fifteen feet : containing both tubules and loess-kind- 
chen in th6 usual varying proportions ; and more or less fossil- 
iferous; It has been quite fully discussed by McGeef- Lists of 
the fossils which are found al)out Iowa City have already been 
published,! and it is not the purpose of this paper to ofifer 
much that is new in this direction, but rather to present a de- 
tailed account of the habits of the local modern molluscs, and 
their bearing ou the loess. 
In probably no other locality in the country have these mod- 
ern and loess faunas been studied side by side more fully than 
at Iowa City. Besides the early work of Witter, and that of 
Keyes (chiefly upon State University Museum specimens col- 
lected and identified by the writer), the efforts of Pilsbry and 
Bayard Elliott were especially noteworthy, though the former 
published but little, while the latter made no permanent record 
of his observations, but submitted a part of his collection to 
the present author, who has been engaged in loess and mollusc 
studies with more or less interruption for many years, and has 
gathered together great numbers of both fossil aind modern 
forms which bear on this question. 
The lists representing these faunas are therefore more com- 
plete than is possible where resident observers are not engaged 
in the investigation of both branches of the subject, and this 
*Exccrpt from the Bulletin of the Laboratories of Natural Histor3', State 
University of Iowa, vol. v; No. 2, pp. 195-216. 
t?7. S. Geol. Sur., vol. xi. pt. i, 1891. 
JW. J. McOhh. /. c; C. L. Wfbster, Am. Nat , Mav; 1887, p. 419; B. 
Shimek, Am. Geol.. vol. i, pp. 149-152, 188S; Bull. Lab. Nat. Hist., State 
Univ. la., vol. i, pp. 200-209, 1890; etc. 
