580 W. W. DAVIS 



Athyris lamellosa, Brachythyris sub orbicularis , Leptaena analoga, 

 Ptychospira sexplicata, Rhipidomella burlingtonensis , Schizophoria 

 swallovi, and Chonetes multicostus, are not limited to the Burlington; 

 but the Lower Burlington seems to be the upper limit of Chonetes 

 multicostus, Lepiaena analoga, and Ptychospira sexplicata, while 

 Rhipidomella burlingtonensis and Schizophoria swallovi are not found 

 above the Burlington. Two species, Cliothyridina prouti and 

 Productus fernglenensis, are found typically in the Fern Glen, and 

 one species, Spirifer shephardi, is typical of the Pierson limestone 

 of southwestern Missouri, which may be the equivalent of the Fern 

 Glen. The Fern Glen commonly has been classed as uppermost 

 Kinderhook, but it is altogether probable that it should rather be 

 considered as lowermost Osage. Species of the two genera Pseudo- 

 syrinx and Syringothyris are found in the Burlington. One species, 

 Cyrtia inexpectans, which is very rare, has been described from 

 residual chert in Missouri, supposed to be of Keokuk age, and another 

 species, Spiriferella neglecta, is found in the Keokuk, but these two 

 species are the least certainly identified of any of those recorded. 



The brachiopods of the foregoing list are clearly related to those 

 of the early Osage faunas of the Mississippi Valley, as these faunas 

 are developed in Iowa, Illinois, and Missouri, and the formation 

 from which they have originated may be certainly correlated as not 

 younger than the Burlington limestone, and in all probability as 

 Lower Burlington. 



The other elements of the fauna confirm the correlation sug- 

 gested by the brachiopods. The abundance of crinoidal remains 

 immediately suggests the Burlington limestone. Both Dizygo- 

 crinus rotundus and Dorycrinus unicornis are typical Burlington 

 crinoids. Platycrinus is also found in the Burlington, though it is 

 not confined to that formation. The blastoid Cryptoblastus melo 

 is another member of the Burlington fauna and is quite limited 

 in its geologic range. The gastropod Euomphalus latus is another 

 characteristic Burlington species, and both species of Platyceras 

 recorded are reported from the Burlington limestone. The corals, 

 bryozoans, and pelecypods which have been recorded have not 

 been specifically identified, but all the genera recognized are known 

 to be present in the Burlington. 



