DETAILS OF THE SECTIONS 487 



This fauna has been referred by Stose and Swartz, on the authority of 

 Ulrich, to the Salina, but there is nothing in this association which may 

 not be regarded as representing Lower Monroan. This is indeed strongly 

 suggested by Spirifer cf. eriensis, the Klcedenia, and Kloedenellas, espe- 

 cially the form compared with Kloedinia sussexensis (Weller), which in 

 the Lower Monroe is represented by the closely related K. rnonroensis 

 Grabau, and perhaps by the Whitfieldella, which should be compared with 

 W . prosseri Grabau of the Lower Monroe, which is' a direct successor of 

 W. nitida, suggesting that species in its form and size and differing 

 mainly in the character of the dental plates and the spondylioid muscular 

 area. 85 



Rhynchonella (Rhynchotrema) formosa Hall is a Helderbergian spe- 

 cies and is probably a wrong identification. If Rhynchospira formosa 

 Hall is meant, then it is probably identical with R. prcvformosa Grabau 

 from the Greenfield limestone of the Lower Monroe. Trematospira 

 camura is a Magaran form, T. perforata a Helderbergian one. Rliynclio- 

 nella (Uncinulus) vellicata is another Helderbergian form and so is 

 Uncinulus pyramidatus. It is plain that this faunal list has little value ; 

 if it indicates anything at all it is the Monroan age of the formation. 

 In water-lime beds from the upper part of the McKenzie formation a 

 small tergite and several pieces with Pterygotus sculpture were found. 



Conglomeratic limestones above the Keefer sandstone indicate a break 

 in the series, which I believe is filled in by the main mass of the Salina 

 continental deposits farther north. 



The McKenzie formation, exclusive of the Keefer sandstone, is about 

 160 feet thick, and is succeeded by the "Bloomsburg" 86 red sandstone 

 member, which varies in thickness and character from place to place, 

 being 120 feet thick east of Tonoloway ridge. Its character suggests the 

 red Longwood, of which it probably represents a reworked portion. It 

 marks a shoaling or emergence of the Lower Monroe sea-floor and a 

 period of stream deposition. Pseudormorphs of salt crystals occur, indi- 

 cating a partial return to arid conditions. This may have corresponded 

 to Sylvania deposition in Ohio, Michigan, and Ontario, or may have been 

 earlier. 



The succeeding 325 feet of shales and calcareous beds (pari of Wills 

 Creek shale) are mostly light colored, containing Leperditia alia and 

 other ostracods. These suggest an Upper Monroan age, but are not con- 

 clusive. The next succeeding 400 feet of Tonoloway limestones, how 



86 A. W. Grabau: Monroe fossils, p. 1H4. 



86 This is not the Bloomsburg of Pennsylvania, but belongs to a inurli higher horizon. 



