KINDERHO OK FORMA TIONS OF MISSO URI I 3 3 



correlation of the Eureka shale fauna than Williams was able 

 to make. 1 As will be shown, the fauna may be correlated defi- 

 nitely with that of the upper Kinderhook, that portion of the 

 series which lies above the Chonopectus sandstone in the 

 Burlington section. 



The specimens referred to Cyrtina aciitirostris by Williams are 

 probably not representatives of the typical form of this species, 

 but of a variation which may prove to be an undescribed form 

 which is present in the Sac limestone and in the typical Chouteau 

 limestone. Spirifer ?narione?isis is a common species in the upper 

 Kinderhook. The species recorded as 6". ? compactus Meek is cer- 

 tainly S. pecidiaris Shum., a common and variable species in the 

 upper Kinderhook which possibly runs up into the lower portion 

 of the Burlington limestone. Athyris hannibalensis is only a small 

 form of A. lamellosa, and the two are not specifically distinct. 

 It is common in the upper Kinderhook of southwestern and 

 southeastern Missouri, but has not been recognized in the Bur- 

 lington section. The three forms of Chonetes recorded by Wil- 

 liams are probably all present in the upper Kinderhook. The 

 species of Prodiictus referred to P. hallanus Wale, is not that 

 species, but the specimens so identified are identical with a 

 common species in the Sac limestone which has also been recog- 

 nized in the typical Chouteau of central Missouri and in the 

 upper beds of the Kinderhook in southeastern Missouri. The 

 pedicle valve resembles P. hallanus, but the brachial valve does 

 not have the concentric markings of that species. The orthids 

 recorded by William are like those in the upper Kinder- 

 hook faunas elsewhere. Lcptaena rhomboidalis is present in 

 almost every upper Kinderhook fauna but has not been recog- 

 nized in the Chonopectus fauna, nor in that of the Louisiana 

 limestone. The additional species recorded by Williams afford 

 little evidence as to the age of the fauna. 



1 Many of the Arkansas collections studied by Williams were made by the writer 

 as an assistant to Professor Williams under the auspices of the United States Geo- 

 logical Survey. These collections were also carefully studied by the writer in 

 Professor Williams' laboratory during the winter of 1894-5. 



