History of the Missouri Paleozoic. — Broadhead. 381 
Chouteau Limestone group 200 
Devonian 100 
Upper Silurian , B60 
Lower Silurian to the base of the Trenton 400 
. 4. Kin 
Ozark series, including: 
First Magnesian limestone 130 
First or Saecharoidal sandstone (St. Pater's). . . 130 
Second Magnesian limestone 230 
Second sandstone 123 
Third Magnesian limestone 350 to 600 
Th i rd sandstone 50 
Fourth Magnesian limestone 300 
1.31q 
Total 3,475 
Below the Trenton formation in southern Missouri the 
Ozark series therefore presents a great thickness of magne- 
sian limestone with occasional beds of sandstone. In the well 
at the Insane Asylum at St. Louis the borings would indicate 
2,000 feet of this series. Prof. Swallow applied to them the 
term "Magnesian Limestone series, ' r but the objection to the 
term is that there are magnesian limestones of other ages. As 
the series is well developed in the Ozarks, and the Ozark area 
is so great, it seems that of all names there is none more ap- 
propriate than "Ozark Series." As such I have named and 
described it in an article published in the American Geolo- 
gist for July. 1891. 
In southeastern Missouri the continuity of the Ozark series 
is not preserved in the same manner as represented elsewhere, 
but is thus : 
First Magnesian limestone 130 
First or Saecharoidal sandstone 133 
Second Magnesian limestone 1 ;."> 
Second sandstone; lower beds chert y 125 
Third Magnesian limestone with cherl and quart/.. . . . •.''.!."> 
Gritstone and Lingula beds 50 
( )/.ark marble 25 
Lower sandstone and conglomerate 90 
Total !».->:: 
These rest on the Archaean porphyries and granite. The 
thickest development of tin- terranes between the < >zark series 
and the top of the Lower Carboniferous Dr. Shumard has es- 
timated to be over 1,800 feet in Cape Girardeau county. lie 
