Loess of loz^'Li City — Shi nick. 345 
fact, coupled with the comparative richness of both faunas, 
makes a comparison of them especially interesting^ and sug- 
gestive. Since all of the fossils which have been found at 
Iowa Cit_y are molluscs, and belong with few exceptions to the 
local modern molluscan fauna, a study of the habits of the liv- 
ing species is of the highest importance because of the light 
which is thus thrown upon the conditions which existed during 
the deposition of the loess. The species included in this list 
are therefore grouped according to habit in order that com- 
parisons and conclusions may be facilitated. All notes on dis- 
tribution, etc. of both modern and fossil shells in the following 
list have reference to the vicinity of Iowa City only, unless 
otherwise specifically stated. "Western loess" means that of 
western Iowa and eastern Nebraska. The material was abund- 
antlv collected and studied in the field by the author, and is 
now in his private collection. 
The names of the local fossil (loess) species are preceded 
bv two asterisks. Those which have been found fossil in the 
loess in other localities, but not at Iowa City though now found 
living here, are marked by one asterisk. The latter series does 
not however include all the species of the modern fauna of 
Iowa Citv which were reported in the earlier Missouri and 
Nebraska lists of loess fossils, as no specimens are extant and 
the species are not now known to occur in vmdoubted loess. 
The species living near Iowa City but not represented in the 
loess are unmarked. The territory covered by this report is 
included within a radius of six miles from Iowa City. 
RECENT AND FOSSIL :^rOLLUSCS AT IOWA CITY. 
I. Spectes here found oxly .\s fcssils. 
**PVRAMIDULA .SIIIMEKII (PUs.) Sllilll. 
Quite common in the loess of Iowa City, which furnished 
the type specimens. A more complete discussion of this species 
is given on pp. 13Q-145 of this Bulletin. 
**PVRAMIDULA STRIGOSA lOWEXSIS PUs. 
This variety is now extinct. All other forms of this ex- 
tremely variable species however belong to the dry western 
plateaus and mountains. It is locally quite common in the 
loess, and the type specimens were from this locality. 
**PUPA MUSCORUM (L.) . 
