274 TRANSACTIONS OF THE [maR. 15, 



11. Pteronites hopkinsi. 



This heretofore undescribed species is not similar to any de- 

 scribed American species, and its evidence is nothing. 



12. Pteronites Isevis. 



Like the preceding species, this one affords no evidence as to 

 the age of the formation. 



13. BIyalina arkansana. 



The genus Myalina is more typically- characteristic of the 

 upper Carboniferous faunas, though it is present in the Osage 

 and St. Louis groups. The evidence afforded by the species is 

 slight, but is towards the Kaskaskia rather than the St. Louis 

 age of the formation. 



14. Lithophaga'^ batesvillensis. 



The most closeh' allied species of the genus is L. pertenuis^ 

 described from the Warsaw beds of the St. Louis group. 



15. Aviculopecten batesvillensis. 



This species is quite distinct from an^^'other American species 

 of the genus, and affords evidence toward neither of the forma- 

 tions in question. 



16. Aviculopecten sp. 



This species affords no evidence bearing upon the present 

 problem. 



11. Allorisma ivalkeri. 



This species, though very much larger, is similar to A. 

 maxvillensis from the Maxville Limestone. It is not closel}^ 

 allied to any species of the typical St. Louis or Kaskaskia form- 

 ations. 



18. Allorisma arkansana. 



This species affords no evidence of the age of the fauna in 

 which it occurs. 



19. Schizodus batesvillensis. 



The most closely' allied species is S. chesterensis^ one of the 

 most characteristic species of the upper beds of the Kaskaskia 

 group. A species referred to S. chesterensis by Whitfield oc- 

 curs in the Maxville Limestone, and the Batesville specimens 

 more closely agree with the Maxville Limestone specimens than 

 with the tj'pical S. chesterensis. 



