24 



CRETACEOUS DEPOSITS OF THE EASTERN GULF REGION. 



In determining the fossils and preparing the lists on which the tables are based the writer 

 was hampered by the fact that the types of many of the species were not at hand for comparison 

 and that he had to depend on published descriptions and illustrations. The lists must therefore 



be regarded as of a preliminary 

 character. For this reason it 

 is to be expected that the ex- 

 haustive studies of the faunas 

 of the region soon to be under- 

 taken will show the necessity 

 for many changes in nomencla- 

 ture and will reveal some errors 

 in the determinations of genera 

 and species. It is also to be 

 expected that some species now 

 regarded as restricted in range 

 within certain limits will be 

 found also at higher or lower 

 horizons. But this lessening of 

 the number of restricted forms 

 wiU probably be offset by the 

 discovery of new restricted 

 forms, and by the recognition 

 of specific differences in forms 

 now regarded as having wide 

 vertical ranges. It is believed, 

 however, that such changes as 

 are found necessary will be of 

 minor importance as regards 

 their effect upon the major conclusions reached through these preliminary studies. Many 

 questionably identified species and many forms identified generically only have been omitted 

 from the tables. 



Table 1. — Range of Cretaceous fossils in irestern Tennessee." 

 [Area 1 on sketch map, fig. 2.] 



Figure 2. — Sketch map showing areas of paleontologic collections listed in Tables 1 to 8. 

 numbers on the map correspond with the numbers of tho tables. 



The 







Impure 





Ripley for- 



phase of 





mation. 



Selma 

 chalk. 





Exogyra 



Exogyra 





costata 



pondcrosa 





zone. 



zone. 



Species. 





1 



o 



si 







a jj 





^ ° 







!» g 





So 





Cj v. 



s 5 





'{■ 





si 





11 



1*1 





72 



8° 



^c 



T3 



j: 



j, si 





- 



KJ 



a a 



Mollusca: 















x 









X 









0. larva Lamarck 





X 



X 



X 





X 



X 



X 











x 



X 









X 



X 





X 



X 













X 



x 











X 









x 









X 



X 



X 







x 



X 









X 















a The numbers are the collection numbers of the U. S. Geological Survey; the collections are in the D. S. National Museum. 

 I 927. — Selmer-Adamsvillo road, 3 miles west of Adamsville. Tenn. L. W. Stephenson, collector. 



- -I.exington-Chesteiville road, about 7 miles east of Lexington, Tenn. L. W. Stephenson, collector. 

 - — selrrKT-Adamsville road, one-quarter mile west of Adamsville. Tenn. L. W. Stephenson, collector. 

 6929.— Adamsville-Conee Landing road, about 4 miles southwest of Coffee Landing. Tennessee River, Tenn. L. W. Stephenson, collector. 



