GEOLOGY AND PALEONTOLOGY OF THE CANAL ZONE. 



199 



The " coral limestone," formerly referred to the top of the Vicks- 

 burg group, as will be shown on subsequent pages, is, in my opinion, 

 equivalent to the basal part of the Chattahoochee formation. The 

 following is a list of the species of corals at present known from the 

 Vicksburg group: 



Fossil corals from the Vicksburg group. 



Name. 



Flabellum magnocostatum Vaughan 



rhornboideum Vaughan 



Turbinolia insignifica Vaughan ." 



Steriphonotrochus pulcher Vaughan 



A rchohelia neglecta (Vaughan) 



vicksburgensis (Conrad) 



mississippiensis (Conrad) 



harrisi (Vaughan) 



aldrichi (Vaughan) 



A ntiguastrea cellulosa (Duncan) 



Balanophyllia elongata Vaughan 



caulifera (Conrad) 



caulifera var. multigranosa Vaughan. 

 Dendrophyllia new species 



Byram 



calcareous 

 marl. 



Marianna 

 limestone. 



Glendon 

 limestone 

 member. 



Mint 



Spring 



calcareous 



marl 

 member 



Red 

 Bluff 

 clay. 



This fauna is different from any now known in the West Indies or 

 Central America. It lived under conditions closely similar to those 

 under which the Jackson fauna of the same area lived. It is impor- 

 tant to note that Antiguastrea cellulosa, a species very abundant in 

 the middle and sparingly present in the upper Oligocene, occurs in 

 the uppermost beds of the Vicksburg group. The Oligocene coral reef 

 represented by the "coral limestone" at Salt Mountain, Alabama, 

 and at Bainbridge, Georgia, overlies the Vicksburg group, which can 

 with considerable assurance be correlated with the lower Oligocene 

 (Lattorfian) of Veneto and elsewhere in Europe. The greatly- 

 developed Oligocene coral reefs of Antigua are to be correlated with 

 the reefs of Bainbridge. They are therefore stratigraphically higher 

 than the Vicksburg group and are of middle Oligocene (Rupelian = 

 Stampian) age. 



MIDDLE OLIGOCENE. 



ANTIGUA FORMATION. 1 



The following list of species is based on a revision of Duncan's 

 work on the Antigua corals, 2 after a study of his types in the collec- 



1 Name proposed by J. W. Spencer in his paper entitled On the geological and physical development 

 of Antigua, Geol. Soc. London Quart. Journ., vol. 57, pp. 496^98, 1901. See also, Brown, Amos P., 

 Notes on the geology of the Island of Antigua, Acad. Nat. Sci. Phila. Proc. for 1913, pp. 584-616, pis. 18-20, 

 1913. Vaughan, T. W., papers referred to in footnote on page 193; and Memorandum on the geology and 

 groundwaters of Antigua, B. W. I., Imperial Dep 't of Agriculture West India Bull., vol. 14, No. 4, 5 pp., 

 1915. 



2 Duncan, P. M., On the fossil corals of the West Indian Islands, Part 1, Geol. Soc. London Quart. Journ- 

 vol. 19, pp. 408-458, pis. 13-16, 1863; Part 4, Idem., vol. 24, pp. 9-33, pis. 1, 2, 1867. 



37149— 19— Bull. 103 2 



