Geology of the St. Croix Dalles. — Berkey. 273 
The principal localities are Franconia, Chippewa river, 
Trempeleau, Minneiska, Black river, Marine Mills and Kicka- 
poo river. 
Fossils from this formation are poorly preserved. No part 
of the shell is present and this sandstone is so friable as to 
render the casts which alone represent the fauna extremely 
fragile materials to work upon. 
The Dresbach sandstones and shales are in great contrast 
to the Franconia sandstone. Whereas in the Franconia for- 
mation there are no shells and few casts; on the contrary, in 
the Dresbach shales immediately below they are so abundant 
that a single hand specimen from a favorable point contains 
hundreds of fragments of brachiopod shells. The range of 
species is limited and the considerable addition which is made 
in this paper as to variety of forms has not indicated a very 
extended geographic distribution. These new forms are de- 
scribed in a later chapter. Fossils reported from the Dres- 
bach at Taylor's Falls and St. Croix Falls are : 
Lingiila ai/ip/a Owen. 
L. anfiqita Hall. 
{Lingnlepis pinnifonnis (^wen.)* Li)igiilepis aciiini)iata Con. 
OholeUa polita Hall. 
In addition to these the following were found recently 
by me: 
Hyalithcs piiinordialix Hall. 
Hypselocoims {Metoptoma) recurvus (Wliitfield). 
Agrauhts convextts Whitfield. 
PtycJwparia cafymenoides Whitfield. 
and a considerable number of new species which arc de- 
scribed in a following chapter. Other localities ha\e re- 
ported the following species from this horizon: 
Crepicephtjhis [Conocephalites) eos Hall. 
Dicelloccpheihis iowensis Owen. 
Pfychoparia {Co)Wccphalites) )ninor Shumard. 
Hyalithcs priinordiatis Hall. 
Ptatyccras priiiiordiatix Hall. {Sctevogyra probably.) 
In addition to these foregoing species noted with compara- 
tive certainty under their respective formations, there are a 
*A recent article by C. D. Walcott makes Lingulepis pinn i fortius 
Owen a synonvm for Lingulepis acuininata Con. 
