50 Trans. Acad. Sci. of St. Louis. 



York Hamilton and Chemung faunas, and the abundance of 

 the two species of Palaeoneilo may be considered as Devonian 

 elements in the fauna. It is not surprising, however, to find 

 such an element in a fauna contained in strata lying almost at 

 the base of the Carboniferous. 



Aside from the twenty-four species already considered, the 

 following eight species described here for the first time, 

 deserve consideration : — 



A'luhocoelia parva. Promacrus websterensis. 



Crenipecten laevis. Edmondia missouriensis. 



Modiomorpha northviewensis. Mouiionia northviewensis. 



Cardiopsis erecta. Plalyschisma missouriensis. 



The genera are mostly those occurring in the Kinderhook 

 faunas elsewhere. Ambocoelia parva is allied to A. minula 

 of the Kinderhook, and also to the Devonian species A. um- 

 honaia. Promacrus websterensis is most closely allied to P. 

 missouriensis from the Kinderhook in Pike County, Missouri, 

 but it is also less closely allied to P. andrewsi which was de- 

 scribed from the Waverly group in Ohio. The genus Plaly- 

 schisma is here recognized for the first time in America. In 

 Europe it is represented by several species in the Carbonifer- 

 ous limestone. To the genus Mourlo7iia, several species, both 

 Devonian and Carboniferous, usually placed in Pleurotomaria, 

 will probably have to be added. 



EXPLANATION OF ILLUSTRATIONS. 



Plates II.-VI. 

 (all of the figures are of natural size.) 



Plate II. — 1, Promacrus missourie7isis SwalL A copy of Meek's figure of 

 this species, introduced here for comparison with P. websterensis. — 2, JVo- 

 macTus websterensis n. sp. Lateral view of one of the type specimens. 



Plate III. — 1, Promacrus websterensis n. sp. One of the type specimens 

 showing the long groove near the dorsal margin posterior to the beak. — 2, 

 Promacrus cuneatus Hall. Lateral view of a nearly perfect left valve. — 

 3-4, Cardiopsis9 erectus n. sp. View of a perfect right valve and a profile of 

 the same in outline. — 5-6, Cardiopsis radiata M. & W. View of a perfect 

 right valve and a profile of the same in outline. — 7, Sanguinolites webster- 

 ensis n. sp. Lateral view of a nearly perfect right valve. — 8, Macrodon sp. 

 Lateral view of a nearly perfect right valve. — 9, Elymella missouriensis 



