FAUNAL RELATIONS 



285 



shales beneath. When the latter come to be more thoroughly investi- 

 gated it probably will be found that they carry a much larger variety 

 of forms than is now known. All the most abundantly occurring forms 

 of the lower Kinderhook and about half the total number of species are 

 also found in the Grassy Creek terrane of the same locality. 



Fifty miles southwest of Louisiana, on Snyder creek, near Fulton, in 

 Callaway county, Missouri, there are, above the Callaway (Middle De- 

 vonian) limestone, 50 feet of green and blue shales. These are highly 

 fossiliferous, and contain besides more than 100 other species, such forms 

 as the following : 



Acervularia profunda Hall. 



Aulopora sp ? 



Leioclema occidens Hall. 



Melocrinus lyelli Rowley. 



Melocrinus gregeri Rowley. 



Aristocrinus concavus Rowley. 



Alhyris minima Swallow. 



Atrypa gregeri Rowley. 



A try pa hystrix Hall. 



Atrypa reticularis Linnaeus.. 



Crania crenistrlata Hall. 



Crania famelica Hall and Whitfield. 



Cyrtina umbonata Hall. 



Dielasma calvini Hall and Whitfield. 



Hypothyris sp ? 



Leiorkynchus sp? 

 Megalanteris sp? 

 Orthothetes panaora Billings. 

 Pentamerella saliensis Swallow. 

 Productella callawayensis Swallow. 

 Productella marquessi Rowley. 

 Pugnax alius Calvin. 

 Schizophoria macfarlani Meek. 

 Spirifer asper Hall. 

 Spirifer annse Swallow. 

 Spirifer euryteines Owen. 

 Stropheodonta altidorsata Swallow. 

 Naticopsis gigantea Hall. 

 Orthoceras sp ? 



These shales lie immediately beneath the Chouteau limestone, which 

 is only a few feet thick at this point and is followed by the Burlington 

 limestone with all its characteristic fossils. The Snyder shales appear 

 to be stratigraphically continuous with the Grassy Creek shales In part, 

 they may also represent the Hannibal shales. 



The peculiar fauna having a strong Devonian facies, which has lately 

 been discovered * in the Kinderhook shales, near the base of the exposed 

 section at Burlington, Iowa, has already been noted. 



The fauna of the highly fossiliferous layers at the base of the Louis- 

 iana limestone at the type locality recalls at once the familiar assemblage 

 of depauperate forms that occurs near the top of the Cedar Valley lime- 

 stone at so many places in Muscatine county, Iowa. Should, on crit- 

 ical comparison, the faunas of these two localities prove to be biologically 

 the same, we would have additional evidence of the wonderful astuteness 

 with which Hall surmised the faunal equivalency of the beds so widely 

 separated geographically. 



*Proc. Iowa Acad. Sci., vol. iv, 1897, p. 



