270 Tlie American Gcologisit. May, imis 
GEOLOGY OF THE ST. CROIX DALLES. III. 
By Charles P. Berkey, Minneapolis. 
(Plates XVII-XXI.) 
Part III. PALF.ONTOLOGY. 
Chapter I. Rcviczv of the Fauna. 
Since the publication of the reports of Owen* and Hallt 
upon this and neighboring locaHties, there have been few ad- 
(Htions to the fainia of the lowest rocks of the upper Missis- 
sippi vahey. The most notable exception to this statement is 
the work by Whitfield. $ This period of comparative inactivity 
is the result of the greater innnediate demand for investigation 
in other directions rather than any tendency to consider this 
field exhausted. In this connection it is interesting to read 
the words of Hall from his general summary (op. cit.) of the 
faunas of this region. He says: "Whenever this localjtv, and 
the region about it, shall be more fully investigated, we may 
confidently predict that additions of much value and interest 
will be made to the primordial fauna of the Upper Mississippi 
valley." P. 180. 
A protracted search in the last tw'O seasons has revealed an 
extensive group of fossils many of which are believed to be 
undescribed. These forms belong to the Basal Sandstone 
series and, in order that a better understanding of their re- 
lationship may be secured, a summary of the species previ- 
ously described from overlying strata is here added. 
Mag/iesiaii Series. The uppermost representative of this 
series within the district is the y^;'rc/c?// sandstone. The follow- 
ing species are found in this formation. 
BclleropJion an/igitafiis Whitfield. 
Pleurotomaria (Holopcix) sweeti (Whitfield) S;ir. 
Ophileta sp. (?) 
Mitrchisonia sp. (?) 
Lingitla stoncana Wliitfield. 
Or this pepifia Hail. 
Raphistoma nihinesotense (Owen) Sar. 
Tryblidiuin (Metopt07na) barabiwnsis (Whitfield). 
Agnostus dispaj-ilis Hall. 
*Owen: Geol. Surv. of Wisconsin, Iowa and Minnesota, 1852. 
tHall: i6th Rep. N. Y. Mus. Nat. Hist., 1863. 
^Whitfield: An. Rep. Geol. Surv. of Wisconsin for 1877. Geology 
of Wisconsin, vol. IV, 1882. 
