Central lotva Section of the Miss. Series. — Bain. 319 
This phase of the Saint Louis is the one generally present 
in Marion county; it is frequent in Mahaska and not unusual 
in Keokuk county, being seen in the small quarries east of 
"What Cheer, similar openings near Sigourney, and occasion- 
ally along the Skunk river. In Washington county the suc- 
ceeding erosion has very generally cut it away, though at 
Brighton it is typically preserved. 
The greater portion of the fossils which are labeled as 
Saint Louis and as coming from this region are from these 
layers. The fauna is more abundant perhaps in number of 
individuals than of species though the latter are not few. It 
is very largely made up of brachiopods and other open sea 
forms and includes among many others the following species: 
Spirifer littoni Swallow, Athyris subquadrata Hall, Produc- 
tus maryinocinctus Prout, Pentremites koninckiana Hall, and 
Zaphrentis pell a ens is Worthen. 
Detailed paleontologic work has not yet been done in any 
of the region. 
Verdi beds. — Preceding the' quiet waters in which the Pella 
beds were laid down there was a period in which apparently 
there were many and rapid changes. This period is marked 
by a series of rapidly alternating sandstones and limestones. 
These individual layers are rarely of more than very local ex- 
tent and have no stratigraphic value. The sa,ndstones are in 
part fine-grained, white, calcareous, and in part coarse and 
ferruginous. The limestones are compact, fine-grained, ash 
gray in color and break with a clear conchoidal fracture. 
They are very rarely fossiliferous. Frequently they become 
brecciated, and it is this particular phase which once gave 
name to the entire formation. The breccia consists usually 
of small, roughly angular blocks of limestone from one-half to 
two and one-half inches in diameter, cemented by a calcare- 
ous cement. In weathering, the differences between the brec- 
ciated blocks and the matrix are made very apparent. The 
brecciation is in places very fine and seems to grade into a 
true oolitic structure, such as is characteristic of the Bedford 
stone of Indiana. Again the brecciation maj'' become of a very 
coarse type and the calcareous matrix be replaced by loose or 
partially consolidated sands. 
In the old railroad quarry near Verdi station in Washing- 
