838 E. O. ULRICH CORRELATIONS OF CHESTER FORMATIONS 



conditions found in southern Illinois occur in the interval between the 

 Bethel and Cypress sandstones. In southeastern Caldwell this interval 

 has expanded and is occupied by the Gasper, consisting for its greater 

 part of thick-bedded oolite and subcrystalline limestones aggregating 

 100 feet or more in thickness. 



The lower 30 to 45 feet of this mass, commonly referred to as the 

 Lower Gasper, is full of Pentremites, more or less dismembered crinoid 

 remains, simple and loosely composite cup corals, and shells of various 

 kinds. The Pentremites are represented by excellent specimens of many 

 species which together form a highly characteristic association. Among 

 the crinoids recognizable calyces of Talarocrinus only are commonly 

 found. In fact, this is preeminently the Talarocrinus zone, no less than 

 9 or 10 clearly distinguishable species of this genus being found in this 

 bed in Kentucky. Of other crinoid remains, pieces of large columns 

 sometimes attaining a diameter of three-quarters of an inch or more are 

 always present. These may be counted as characteristic of the bed, as 

 columns of equal size are only rarely found above the shale bed which 

 commonly separates the Lower Gasper from the upper limestone of the 

 formation. 19 The corals, too, are to a considerable degree characteristic. 

 This is true particularly of the largest and most broadly conical of the 

 cups, apparently an undescribed species of Cyathophyllum. 



This Lower Gasper bed is terminated above by a widely though not 

 generally distributed bed of calcareous marls and shale, with thin, highly 

 fossiliferous layers of limestone.. This shale bed often is not recognizable 

 to the south of Kentucky, but on tracing the formation eastward into 

 Breckenridge County it passes into a sandstone member to which Mr. 

 Butts has applied the name Sample sandstone. This sandstone extends 

 thence northward into Indiana, and from there probably turns westward, 

 under cover of later formations, to reappear in southern Illinois as the 

 Yankeetown sandstone. Whether this belief is correct or not, it is 

 positively established that the Sample sandstone has nothing to do with 

 the Bethel sandstone. 



The bulk of the fossils in this Middle Gasper shale member consists 

 of Bryozoa, and these mainly of flabellate Fenestellida? ; but among the 

 others Cystodictya labiosa is perhaps the most abundant, The axes of 

 Archimedes are mostly of small types and only rarely if ever very 



19 Such columns have been observed above the Lower Gasper at only a few places in 

 Kentucky. Most notable of these is Russellville, where they were found in the bed be- 

 fore described as containing Amplejcus geniculatus. It is an interesting confirmation of 

 the conclusion tentatively held in that discussion to note the fact that the same kind 

 of column was collected together with the mentioned coral also in Union County, Illinois. 



