GEOLOGY AND PALEONTOLOGY OF THE CANAL ZONE. 571 



and apparently Mr. K. B. Newton agrees with them. 1 The papers 

 •cited below contain the opinions referred to, and additiomal references 

 to literature are given in the footnotes to Doctor Dall's paper. On 

 page 211 of this volume, under my discussion of the successive Amer- 

 ican coral faunas of Tertiary age, the same opinion is expressed. 

 Paleontologists are divided in opinion as to whether the Aquitanian 

 should be referred to the Oligocene or to the Miocene. 



From my experience with American faunas I incline to consider 

 it as belonging to the older series. The Kupelian (basal Chatta- 

 hoochee and Antiguan) fauna has much in common with the 

 Sannoisian-Lattorfian (Vicksburgian) faunas, on the one hand, and 

 with the Aquitanian (Tampa) fauna on the other. The failure to 

 discover Lepidocyclina at Tampa seems to me of no great value as 

 evidence, for, so far as I am aware, no careful search for Foraminifera 

 has been made in the "silex" bed. Should the specimens not have 

 been destroyed by changes in the sediments subsequent to deposition, 

 it is my expectation that either Lepidocyclina or Hcterosteginoides, 

 or both, will be found at Tampa, for in the Canal Zone both of those 

 genera of Foraminifera are found in association with a fauna that 

 I am correlating with the Tampa, and Heterosteginoides occurs in 

 Anguilla. Mr. Newton, in his note cited, states that "Nummulites 

 died out at the end of Oligocene time, being replaced by Lepidocycline 

 Foraminifera in the succeeding Aquitanian and later stages of the 

 Miocene period." This is an unfortunate remark, for the type-species 

 of Lepidocyclina is L. mantelli (Morton) from the Vicksburgian Oligo- 

 cene of the Gulf States. It is now known that in Georgia the genus 

 ranges stratigraphically as low in the Eocene as a middle Jacksonian 

 horizon, overlapping the upward range of OrtJiopliragmina, 2 and it is 

 probable that it ranges as low as the base of the Jackson formation in 

 Mississippi and Louisiana. Nummulites panamensis in the Canal Zone 

 •occurs at a horizon very nearly the same as that of the "silex" bed 

 at Tampa. There are important differences between the Tampa 

 and the later fauna of the Chipola marl, which is considered by the 

 students of Florida stratigraphy, except Doctor Dall, as the basal 

 member of the Alum Bluff formation. However, it should be recog- 

 nized that the presence of the Chipola marl considerably west 

 of the type locality on Chipola River indicates a persistence 

 that may warrant according it formational rank. I am definitely 

 placing the Chipola marl and the higher members of the Alum Bluff 

 formation in the Miocene. 



1 Dall, W. H., Note on the Oligocene of Tampa, Fla., the Panama Canal Zone, and the Antillean region, 

 Malacolog. Soc. Proa, vol. 12, pp. 38, 39, 1916. 

 Newton, R. B., Remarks on Dr. Dall's paper, idem, p. 40. 

 * Generic determinations by Dr. Joseph A. Cushman. 



