GA SSUMCATMONIOLNOPPAR (Le OZOLOROCKES. OOK 
considerable number of species; but in the massive limestones 
the number of species and individuals is usually smaller. 
From the exposures of shales and limestones on Mill Creek, 
the following species were obtained, which are arranged in the 
order of their relative abundance and may be considered the 
characteristic fossils of the formation: 
1. Chonetes granulifera, Owen. 
2. Productus (Marginifera) splendens, Norw. and Pratt. 
3. Productus semireticulatus, (Martin) de Koninck. 
4. Productus cora, d’Orbigny. 
5. Spirifer (Martina) planoconvexus, Shum. 
6. Fusulina cylindrica, Fischer. 
7. Athyris (Seminula) subtihita, (Hall) Newb. =A. argentea, 
(Shep.) Keyes. 
8. Pugnax uta, Marcou (Marcou) Hall and Clarke. 
9g. Productus nebrascensis, Owen. 
10. Hustedia mormonit, (Marcou) H. and C. 
11. Septopora biserialis, (Swallow) Waagen. 
12. Khombopora lepidodendroides, Meek. 
13. Spirifer cameratus, Morton. 
14. Pinna peracuta, Shum. 
15. Phillipsia scitula, Meek and Worthen. 
16. Derbya crassa, (Meek and Hayden) H. and C. 
17. Meekella striato-costata, (Cox) White and St. John. 
18. Chonetes Flemingi, (according to Keyes) Norw. and Pratt. 
19. Allorisma Geinitzit, Meek (7) 
20. Campophyllum torquium, (Owen) Meek? 
21. Chonetes glabra, Geinitz=C. levis, Keyes. 
22. Productus symmetricus, McChesney. 
23. Spiriferina kentuckensis, Shum. 
24. Enteletes hemiplicatus, (Hall) H. and C. 
25. Dielasma bovidens, (Morton) H. and C. 
26. Orbiculoidea nitida, (Phillips) H. and C. 
27. Myalina subquadrata, Shum. 
28. Allorisma subcuneatum, M. and H. 
29. Aviculopecten occidentalis, (Shum.) Meek and Worth. 
