135 Midway Stage 21 



and 5 the clayey sand bed: 



1. Corbula subcompressa Gabb, - - ~ 1 ^' 



2. Venus ripleyana Gabb, - - * ^' •^• 



3. Crassatella pteropsis Oahh, - - ' . ' ^' 



(Conrad had previously given this name to a species of 



CrassateUa; Jour. Phila. Ac. iv, 279. I [Safford] there- 

 fore propose C. gabbi for it. 



4. C. monmouthensisf Gabb, - - - •^' 

 Cardiia subqiiadrataf Gabb, - - - ^. 

 Leda protexta Gabb, - - - " •^• 

 Modiola saffordi Gabb, - - - - I, s. 

 Ostrea denticulifera Con., - - - ^- •^• 

 O. cremilhnarginata Gabb, - - - ^. 



(If No. 8 is referred to the proper species, then O. cren- 

 ulimarginata Gabb is, I [Safford] think, its lower or larger 

 valve. 



10. Gryphaa votner M-orX.. , - - " ^• 



1 1 . Turritella tennesseensis Gabb, - - " "^^ 



12. T. saffordi Oobh, - - - - I, s. 



13. T. kardema7iensis Gahh, - - - ' 7 ^' 



14. T. pujni/a Gahh, - - - - I, s. 



15. Natica redilabrum Con., - - - - ^. 



16. Fasciolaria saffordi Oobh, - - - ■^• 



17. Neptunea impressa Gabb, 



s. 



18. Callianassaf gwyni '$>Q&ox^, - - - /, 



19. Lamna gracilis? Ag. , 



20. Crocodilusf (tooth) - - - " ^ 7 "^' 

 " It will be seen that but two species of those given, Gryphcza 



vomer and Natica rectilabrum , are common to this group and the 

 Green Sand. Localities in Mississippi, however, furnish series of 

 fossils which unite the groups more intimately. " , ., , 



The Gryphaa vomer is doubtless an Ostrea pulaskensis, while the 

 Natica rectilabrum is not the Cretaceous form described by Conrad 

 under that name; this has been ascertained by a comparison of 

 typical' Cretaceous species from Mississippi with Dr. Safford' s 

 specimens. By referring to Part II of this Bulletin it will be seen 

 what disposition has been made of the various molluscan species 



named above. j j t -r^ 



^ Specimens from Middleton station kindly forwarded by Dr. 

 Safford show that the Crainesville horizon passes through this 

 place, and, as we learn from other sources, passes through_ Tippah 

 and Pontotoc counties in Mississippi. Dr. Safford' s Middleton 

 specimens include Cucullcza saffordi, Meretrix ripleyana, Veneri- 

 cardia var. of planicosta, Turritella mortoni, Fusus hubbardanus, 

 Calyptrophorus velatus and Levifusus trabeatus var. 



