GEOLOGl' AND PALEONTOLOGY OF THE CANAL ZONE. 193 



faunas of the different habitats mingle. Corals of the same habitat 

 should be compared, or groups of species of the same genera, as I 

 have done for Empire (Canal Zone) and Anguilla, where the habitats 

 are nearly enough alike for the same genus to thrive in both. Un- 

 less it caa be estabhshed that the habitats are ecologically very 

 nearly the same the percentages can not be used safely. 



GEOLOGIC HISTORY OF THE UPPER EOCENE AND LATER CORAL 

 FAUNAS OF CENTRAL AMERICA, THE WEST INDIES, AND THE 

 EASTERN UNITED STATES. 



Eocene. 



brito formation, nicaragua.' 



Dr. C. W, Hayes collected on or near the Pacific coast of Nicaragua 

 the following species: 

 Astrocoenia d'achiardii Duncan. 

 SyzygophyUia liayesi Vaughan. 



ST. BARTHOLOMEW LIMESTONE.2 



I am introducing the name St. Bartholomew limestone for the 

 upper Eocene limestones of St. Bartholomew. Description of the 

 rock, its stratigraphic relations, and summaries of its faunal char- 

 acters are given in the papers referred to in the footnotes. Only 

 two species of corals found in the St. Bartholomew limestone are 

 actually described in the present memoir, namely: 

 . Asirocoenia d'acMardii Duncan. 



incrustans (Duncan) Vaughan. 



The fossil corals from the St. Bartholomew limestone have been 

 specially considered by Duncan ^ and myself. Prof. A. G. Hogbom, 

 of the University of Upsala, kindly lent m.e in 1904 the entire Cleve 

 collection from St. Bartholomew, and in 1914 I spent eight days 

 studying and collecting on the island. I am combining both the 

 Cleve and my collections in the following list, and am adding 

 the names of the Jamaican Eocene species, several of which also 



1 For an account of the Brito formation, see Hayes, C. W., Physiography and geology of region adjacent 

 to the Nicaragua Canal route, Geol. Soc. Amer. Bull., vol. 10, pp. 285^348,1910. Description of the Brito 

 formation, pp. 309-313. 



2 For accounts of the geology of St. BartholomeTv, see as follows: Cleve, P. T., On the geology of the 

 northeastern West India Islands, K. svenska Vet.-Akad. Handl., vol. 9, No. 12, pp. 24-27, 1872. Vaughan, 

 T. W., Study of the stratigraphic geology * * * of the smaller West Indian Islands, Carnegie Inst. 

 Washington Yearbook No. 13, pp. 358-360, 1915; also Yearbook No. 14, pp. 368-373, 1916; [Present status 

 of geologic correlation of the Tertiary and Cretaceous formations of the Antilles], Washington Acad. Sci. 

 Jour., vol. 5, p. 489, 1915; Reef-coral fauna of Carrizo Creek, Imperial County, California, and its signifi- 

 cance, U. S. Geol. Survey Prof. Pap. 9S-T, pp. 362, 363, 1917. 



s Duncan, P. M., On the older Tertiary formations of the West-Indian Islands, Geol. Soe. London Quart. 

 Joum., vol. 29, pp 548-565, pis. 19-22, 1873. 



Vaughan, T. W., Some Cretaceous and Eocene corals from Jamaica, Mus. Comp. Zool. Bull., vol. 34, 

 pp. 227-250, 255-256, pis. 36-41, 1899; A critical review of the literature on the simple genera of the Madre- 

 poraria Fungida, with a tentative classification, U. S. Nat. Mus. Proc, vol. 28, pp. 371-.324, 1905; Study of 

 the stratigraphic geology * * * of the smaller West Indian Islands, Carnegie Inst. Washington Year- 

 book No. 13, pp. 358-360, 1915; The reef-coral fauna of Carrizo Creek, Imperial County, Cahfornia, etc., 

 U. S. Geol. Survey Prof. Pap. 98-T. pp. 362-363, 1917. 



