GEOLOGY AND PALEONTOLOGY OF THE CANAL ZONE. 211 



TAMPA FORMATION OF FLORIDA. 



The corals from the "silex" bed of the Tampa formation considered 

 in this paper are as follows : 



Orbicella tampaensis Vaughan. 



var. silecensis Vaughan. 



Antiguastrea cellulosa (Duncan). 



Siderastrea silecensis Vaughan. 



Siderastrea Mllsboroensis Vaughan occurs at about the same horizon 

 as the "silex" bed. 



The Tampa coral fauna has not been described in print, but I 

 furnished Doctor Dall a list of my manuscript names of the species 

 and it appeared in his monograph of the molluscan fauna of the 

 Orthaulax pugnax zone of the Oligocene of Tampa, Florida. 1 I have 

 pointed out that Orbicella tampaensis var. silecensis (see p. 391 of this 

 paper) closely resembles some of the variants of 0. costata from An- 

 guiUa and that the specimens identified as Siderastrea silecensis in 

 which there are over 60 septa perhaps should be referred to S. con- 

 ferta (see p. 449). Besides the species mentioned, there are species 

 representing the following genera: Stylophora, AntiUia%, Galaxea, 

 Solenastrea, Maeandra, Syzygophyllial, Endopachys, Acropora, Gonio- 

 pora, Porites, and Alveopora. 



Two and perhaps three of the "silex" bed species of corals also 

 occur at Bainbridge, but the faunas otherwise are not the same. 

 Two of the species from Tampa are near living West Indian and 

 Floridian species. These are Solenastrea tampaensis Vaughan, nomen 

 nudum, which is near S. liyades (Dana) ; and Porites wiUcoxi Vaughan, 

 nomen nudum-, which has the septal arrangement of Porites astreoides. 

 The presence of such species with modern affinities seems to me to indi- 

 cate a considerably younger age than that of the reefs near Bain- 

 bridge. Furthermore Lepidocyclina is abundant in the reefs near 

 Bainbridge, but has not yet been found at Tampa. Orinaulax pugnax 

 occurs in the "silex" bed at Tampa, but it has not been found in the 

 overlying limestone; the same species Occurs in the base of the An- 

 guilla formation, but I did not find it at higher levels. Dr. C. W. 

 Cooke, who has monographically described the mollusca of the 

 Anguilla formation, correlates it with the Tampa formation on the 

 basis of similarity in their molluscan faunas. The correlation of the 

 Tampa formation is further discussed on pages 570, 571. 



CONCLUDING REMARKS ON THE UPPER OLIGOCENE. 



That there was connection between the Atlantic and Pacific oceans 

 during upper Oligocene time is shown by the continuity of both the 

 Culebra formation and the Emperador limestone from the Atlantic 

 to the Pacific slopes of the Isthmus. On the geologic map, plate 153, 



» U. S. Nat. Mus. Bull. 90, p. 18, 1915. 



