266 S. WELLER FAUNA OF THE FERN GLEN FORMATION 



highly characteristic formation, consisting of beds of red calcareous shales 

 which often graduate into red limestones. The lower limit of the forma- 

 tion is usually sharply defined, but toward its summit it passes gradually 

 into greenish, shaly, calcareous beds, and these in turn merge gradually 

 into the superjacent light colored, cherty Burlington limestone. The type 

 locality of the formation is in the bluffs of the Meramec river, in the 

 railroad cut just west of Fern Glen station, on the Missouri Pacific rail- 

 road, about 20 miles west of Saint Louis. At this locality the section 

 exposed is as follows : 



5. Gray limestone with an abundance of chert ; outcrops mostly covered 

 with soil and talus upon the slope of the hill. This is the typical 

 Burlington limestone Thickness, 25 feet 



4. Greenish calcareous shales with an abundance of chert in bands 

 which are more or less continuous. Toward the base the beds 

 are somewhat variegated with the red color of the subjacent 

 bed . Thickness, 14 feet 



3. Red calcareous shales, highly fossiliferous, with a persistent chert 

 band at the summit 6 inches in thickness. In the midst of the bed 

 occasional more or less continuous chert bands occur, but they are 

 far less conspicuous than in the bed above Thickness, 12 feet 



2. Hard, red, more or less crystalline limestone, with numerous crinoid 

 stems and other fossils similar to those in the superjacent bed. 



Thickness, 14 feet 



1. Hard, tough limestone, similar to that above, but of a buff color. 



Exposed thickness, 2 feet 



In this section beds number 2 and number 3 typically represent the 

 Fern Glen formation, but bed number 4 is a transition from the typical 

 Fern Glen to the Burlington limestone, and although it is not so fossil- 

 iferous as the red beds below, its fossils seem to be identical with them. 

 Under these circumstances bed number 4 should probably be considered 

 as a part of the Fern Glen, making the total thickness of the formation 

 at this point 40 feet. 



Another locality of the Fern Glen formation which has furnished an 

 abundance of fossils is near Kimmswick, Jefferson county, Missouri. 

 This locality is in a railroad cut of the Saint Louis, Iron Mountain and 

 Southern railroad, a little over one mile south of Kimmswick and about 

 2 miles north of the Glen Park section noted in Kinderhook Faunal 

 Studies, number IV, describing the Glen Park fauna. The section at 

 this locality is as follows : 



8. Light colored gray limestone, or often with a greenish color, 

 especially below, with a large amount of chert in bands. At 

 the summit this bed is doubtless true Burlington limestone, 

 but the lower portion represents the transition beds from 

 the Fern Glen to the Burlington Thickness, 20 feet 



