40 THE DEVONIAN OF MISSOURI. 



Feet. Inches. 



Burlington limestone, brown sandy phase 4 4 



Sylamore, gray to brown and green sandstone 1 4 



Snyder Creek shale. 



1. Brown sandstone grading to brown sandy limestone below. All 



very porous. Bears Chonophyllum ellipticum Hall and Whit- 

 field, Stropheodonta demissa (Conrad), Schizophoria striatula 

 (Schlotheim) and Spirifer euryteines Owen 1 10 



2. Hackly thin-bedded, sandy limestone, drab, weathering to yellow. 1 3 



3. Sandy limestone weathering into thin yellowish-brown layers. 



Original color brown. Crowded with Schizophoria striatula 



(Schlotheim) 1 4 



(Almost 100 yards from tne above the top 4' 3" is a rather 

 homogeneous brown sandy limestone. In places crowded 

 with Chonophyllum ellipticum Hall and Whitfield, Stropheo- 

 donta demissa (Conrad). At the top it grades without break 

 into a green sandstone.) 



4. Mainly gray to brown shale, in some places greenish. A few very 



thin beds of sandstone 38 5 



5. Limestone and shale interbedded, mainly limestone, drab to bluish- 



gray, 2 inches very compact fine-grained limestone at the top 



which weathers out in large slabs 4 6 



6. Bluish-gray limey shale 2 6 



Total Snyder Creek shale 49 10 



Callaway, blue hackly limestone with very dark spots making up about half the mass. 



This section is about two miles west of the Cow Creek 

 section given on page 39. Only the top of the Snyder Creek is 

 exposed in the other section and the shales as described there are 

 much like the number 4 of this section. 



The New Bloomfield section as given on page 38 lacks the 

 top part of this section. 



The section on Craghead Creek as given on page 38 lacks 

 all but the lower 23 feet of this section. 



An isolated outcrop a few acres in extent is found north of 

 Bluffton in Montgomery County. At this place the formation 

 is about 20 feet thick and consists of purple limestone and shale. 

 It rests on Callaway, which is only a few feet thick, and is 

 overlain by the Burlington. Fossils occur in abundance, Spirifer 

 euryteines Owen being particularly abundant. 



On the Montgomery City-Danville road, four miles south 

 of Montgomery City, a yellowish sandy shale, of which about 

 8 feet is exposed, outcrops west of the road on the south side 

 of Smith's Branch, and this is the most easterly outcrop on the 

 north margin of the Snyder Creek shale. 



The most northerly outcrops are on Whetstone Creek, 7 

 miles northwest of Williamsburg, where the shales occur in 

 only a few places and are not over 10 feet thick at any place. 



The Snyder Creek shale is overlain unconformably by 

 Sylamore sandstone over most of its extent, but Chouteau 

 limestone, Burlington limestone, and Cherokee shale are occa- 



