Welter — Kinderliook Faunal Studies. 489 



continuous bands a few inches in thickness. Many crinoid 

 stems shown upon the weathered surfaces, with 8pirifer 

 grimesi and other large brachiopods. This bed and those 

 overlying it may be correlated with the Burlington limestone. 

 The line separating the Burlington from beds of Kinderhook 

 age in this section is not entirely clear, but it should probably 

 be drawn at the top of the red bed. 



Thickness, 18 feet. 



From the above section it will be seen that the Glen Park 

 limestone occupies a position immediately above a great un- 

 conformity. This unconformity is not local but is the same 

 great break in sedimentation which is recognized widely 

 throughout the Mississippi valley. The beds below the un- 

 conformity at the locality under discussion, are of upper Or- 

 dovician age, but in many places they are much older; the 

 beds above the same unconformity are everywhere in the 

 Mississippi valley, of late Devonian or early Mississippian age. 

 The determination of the exact age of the Glen Park limestone 

 is wholly dependant upon its faunal characteristics, and will 

 be discussed later, but from the line of unconformity upward, 

 the sedimentation was apparently continuous without a break, 

 and very soon passes into beds which are unquestionably of 

 lower Mississippian age. 



Description op Species. 

 COEC.ENTERA.TA. 



ACTINOZOA. 

 Zaphrentis sp. undet. 



Plate l,fig. 1. 



A few specimens of a small, straight, horn-shaped coral 

 have been observed, but the material is insufficient for its 

 more exact determination. 



ECHINODERM AT A . 



CRINOIDEA. 



AcTiNOCRiNUS? sp. undet. 

 Plate 1, figs. 2-3. 

 Numerous detached crinoid plates, nodose in the center and 



