Report of the State Geologist. 215 



1. S. perextensa, Meek and Worthen. Onondaga limestone. 



2. S. macrothyris, Hall. Corniferous limestone. 



3. S. angusta, Hall. Corniferous. 



4. S. granulifera, Hall. Hamilton group. 



5. S. plena, Hall. Burlington group. 



6. S. Marcyi, Hall. Corniferous and Hamilton. 



7. S. Wortheni, Hall. Hamilton. 



8. S. pennata, Owen. (== S. Atwaterana Miller.) Hamilton. 



9. S. Parryana, Hall. Hamilton. 



10. S. eurutines, Owen. Hamilton. 



11. S. Manni, Hall. Corniferous. 



12. S. audacula, Conrad.= ?S. Medialis Hall. Hamilton. 



13. S. macronota, Hall. Hamilton. 



14. S. fornas, Hall. Hamilton. 



15. S. aspera, Hall. Hamilton. 



16. S. MacBridie, Calvin. Hamilton. 



17. S. alta, Hall. Chemung. 



18. S. extenuata. Kinderhook. 



19. S. Carteri, Hall. Waverly. 



20. S. texta, Hall. Knobs. 



21. S. subcuspidata, Hall. Keokuk. 



22. S. propinqua, Hall. Wai-saw. 



23. S. Hannibalensis, Swallow.= ?S. typa, Winchell. Kinderhook. 



Under the families Athyrid^, Nucleosperid.e, Atrypid^, 

 ZYGOSPiRiDiE and Rhynchonellid^ we have need of much material 

 beyond that already possessed. In the family of Pentamerid.e 

 we have a pretty good collection for our purpose, though it is far 

 from complete and will need considerable additions before com- 

 pleting the volume. 



Of the important family Terebratulid^ we have only very 

 meagre collections and in order to give a respectable representa- 

 tion of most of the genera it will be absolutely necessary to make 

 farther collections in the field or to borrow from collections, as 

 already made by individuals or institutions. The latter method 

 is the only feasible one when we consider the short time in which 

 the volume is to be completed. 



Both the Productid.e and Terebratulid.e are more largely 

 represented in the Carboniferous rocks of the west and to these 

 we must resort for our means of illustrating these families. The 

 Carboniferous forms of Streptorhyuchus are also those most 

 essential for our use in the preparation of this volume. 



