253] W. P. Woodring 55 



The Chipola marl among the Florida horizons has the 

 largest number of species in common with the Bowden. The 

 actual number is of little significance since the Caloosahatchie 

 has almost the same number. It is significant, however, that 

 the Chipolan elements are completely overshadowed by the 

 closer affinities of a large number of groups with Duplin and 

 even "Waccamaw and Caloosahatchie forms. Difficulties are 

 encountered in interpreting these modern elements in terms 

 of age relations to the faunas of the mainland, since obviously 

 considerations of facies and geographical proximity are 

 involved. A larger number of Bowden species are found in 

 the present West Indian waters than in any of the Florida 

 Tertiary faunas and more forms are common to the Caloosa- 

 hatchie than to the Oak Grove, Duplin or Waccamaw. 



The taxodonts supply one-third of the total number of 

 Recent species and all of these are found among the Arcidae, 

 hence that family, and especially the sub-family Arcinae, has 

 a modern aspect. Five Eecent Areas are included in the list 

 and several others are very closely allied to Eecent forms. 

 Four of the Areas that persist to the Recent are found in the 

 Chipola fauna and three in the older Tampa, so that the 

 actual number is of little weight. But a modern element is 

 furnished by the introduction of the section Bathyarca. Two 

 of the three oysters are believed to be identical with Recent 

 species. Among the Pectens are several elements that are not 

 encountered among the Oliocene faunas of Florida; these 

 include an Euvola of modern aspect, several Acquipectens that 

 are most closely related to Pliocene or Recent forms and a 

 Propeamusium of decidedly modern type. Among the remain- 

 ing Prionodesmacea the genera Limcea and Placuanomm are 

 unrepresented in the Oligocene of the Florida section. 



A Crassinella strongly suggests a Duplin and Waccamaw 

 species. Aside from a Recent Chama, the presence of the 

 genus EcJiinocJiama lends to the Chamidae a modern appear- 

 ance. The Lucinacea as a whole present a modern aspect. 

 In addition to several species that are more closely related to 



