D. K. (rreger — Devonian of Central Missouri. 375 



stone to the strata "having their most typical development in 

 Callaway county" he would likewise include beds in Perry and 

 Cape Girardeau counties, which to our knowledge contain an 

 entirely distinct assemblage of fossils, a fauna in fact intimately 

 related to the southern Illinois Devonian, which has been 

 shown by Weller (3), Schuchert (4), and Savage (5), to belong 

 to the eastern or Mississippian Province. 



While we regret that the name Callaway limestone has 

 assumed a place in our literature through a somewhat illegiti- 

 mate course, its retention should be insisted upon since the 

 formation has its greatest development both in area and thick- 

 ness in Callaway county. 



To the upper member of the central Missouri Devonian we 

 would apply the name Craghead Creek shale since the typical 

 exposure of this division is found on Craghead Creek (6), a 

 small tributary of Middle River, south of Fulton about six 

 miles, ou the old Snyder farm. At this place about 35 feet of 

 shale is exposed and the contact with the Mississippian above 

 and the Callaway limestone below are both visible. The 

 discovery of these shales dates back to 1858 and it is quite 

 possible that Dr. S. S. Laws, then president of Westminster 

 College, was the first collector to visit the locality, since it was 

 through him that Prof. Swallow became acquainted with its 

 rich fauna. 



A number of small outcrops of the Craghead Creek shale 

 occur in Callaway county, but it is nowhere so fully exposed as 

 on the Snyder farm, where within a distance of one mile the 

 following section is exhibited: Lower Coal-measures, Upper 

 Burlington, Lower Burlington, Kinderhook, Craghead Creek 

 shale, Callaway limestone, first Magnesian limestone, Sacchar- 

 oidal sandstone. 



Structurally the Craghead Creek shale is readily divisible 

 into three members: the lower portion made up of dark blue 

 and drab shale, with interbedded bands of shaly limestone, 

 highly fossilif erous ; the middle member consisting of a light 

 drab, argillaceous limestone with few fossils, mostly remains 

 of Crinoidea ; the upper member consisting of a light gray, 

 siliceous shale, this like the lower member being highly 

 fossiliferous. 



With the exception of the Brachiopoda and Crinoidea the 

 fossils of the Craghead Creek shale have received only a 

 cursory study, hence the following notes on the fauna are almost 

 exclusively confined to these forms. 



The faunal lists here presented are based on collections made 

 in the following localities. Callaway limestone: Bellama 

 Springs, southeast of Fulton, Auxvasse Church, east of 

 McCredie, and Sampson's Ford, east of Fulton. The Craghead 



