PLATE XX.* 



Illustrating paper by Stuart Weller ou the " Batesville Sandstone of Arkan- 

 sas," pp. 251-282. 



Figs. 1, 2. Pinna arkanmna. 260 



Figs. 3, 4. Aviculopecten hatesvillensis. 263 



Fig. 5. Schizodus ?? sp. 267 



Figs. 6, 7. Allorisma loalkeri. 265 



Figs. 8, 9. Schizodus hatesvillensis. 266 



Fig. 10. Pteronites Jiopkinsi. 261 



Figs. 1\, 12. Pterimifesheris. 262 



Fig. 13. Aviculopecten sp. 264 



Figs. 14, 15. Litlwphaga? hatesvillensis 263 



Figs. 16, 17. Myalina avlansana 262 



* All the .specimens figured are internal casts. 



