xl THE PALEONTOLOGY OF MINNESOTA. 
Moses Strong. 
1878. In volume 11 of the final report of the late Wisconsin survey is a chapter by 
MOSES STRONG on the ‘‘ Geology and Topography of the Lead Region.” Under the term 
Trenton he embraces the Buff and Blue limestones, their total average thickness being. 
about 50 feet. The Blue is divisible into two parts, viz., the ‘‘glass rock,” in heavy lay- 
ers, the lower half, and the other thin-bedded which sometimes graduates into the thin- 
bedded Galena above. At the separation of the Blue from the Galena, occurs almost invar- 
iably, a carbonaceous shale, having a thickness from a quarter of an inch to a foot or more. 
This is considered an unfailing guide to the bottom of the Galena. This shale has its 
greatest thickness in the vicinity of Shullsburg, where it is seven feet thick, the carbonace- 
ous matter amounting to 43.60 p.c. Large quantities of lead, and more particularly of zinc, 
have been taken from the Blue and Buff limestones in southwestern Wisconsin. 
The Galena limestone is a dolomyte and is the chief lead-bearing rock. Itis regularly 
bedded and has a thickness of 200 feet or more. It is apt to weather with an irregular 
surface owing to cavities and softer spots. Its lower portion is interbedded with thin lay- 
ers and irregular nodules of flint. The characteristic fossil of the formation is Recep- 
taculites oweni, found indifferently in all parts. Next in frequency are Streptelasma cor- 
niculum and some species of Orthis. The most infrequent is Maclurea magna, which per- 
tains to the middle beds. Lingula quadrata is quite frequent in the upper beds. Other 
and more infrequent fossils are Pleurotomaria lenticularis, Bellerophon bilobatus, Orthis 
biforata and occasional Orthocerata. 
The Cincinnati, which rarely contains important layers of limestone, has a thickness 
of about 125 feet. The lower beds abound with shells of the Nucula fecunda, and the 
middle ones with Rhynchonella increbescens, Strophomena alternata and stems of Cheaetetes. 
The upper beds contain a few Orthocerata. 
Rh. P. Whitfield. 
1879. Description of new species of fossils from the Paleozoic formations of Wisconsin, by 
R. P. Whitfield; Ann.Rept. Wisconsin Geol. Survey for 1879; Madison, 1880; pp. 44-71. 
Twenty six new species are described in this paper. The Trenton forms,—ten in 
number,—are as follows: 
Trochonema beachi, Buff beds of lower Trenton. 
Endoceras (Cameroceras) subannulatum, upper part of Buff limestone. 
Cyrtoceras planidorsatum, lower part of Buff limestones. 
Oncoceras mumiaforme, Lower Buff limestone. 
Oncoceras brevicurvatum, upper part of Buff limestones. 
Asaphus triangulatus, Blue limestone. 
Fistulipora rugosa, Hudson River shales. 
Streptorhynchus cardinale, Hudson River shales. 
Strophomena wisconsinensis, Hudson River shales. 
Rhynchonella neenah, Trenton, Galena and Hudson River. 
These forms are illustrated in volume tv of the final report. 
