GEOLOGY AND PALEONTOLOGY OF THE CANAL ZONE. 259 



known with approximate completeness. The total coral faunas have 

 yielded some hundreds of species. 



EOCENE REEF CORALS OF ST. BARTHOLOMEW. 



The corals obtained from the St. Bartholomew limestone are listed 

 on page 194. Although there are many specimens and species of reef 

 facies, they scarcely form a reef properly speaking. However, the 

 stratigraphic relations are interesting. The best collecting ground 

 is on the northeast face of the northwestward projecting limb of the 

 island, between Anse Lezard at the northwest and Jean Bay at the 

 southeast. Anse Ecaille lies between the two bays mentioned. 

 Cleve's ^ account of the geologic succession is correct, perhaps with 

 some modification of his dates of a part of the igneous rocks. The 

 base of the section is composed of volcanic agglomerate, above 

 which there is interbedded agglomerate or sandstone, conglomerate 

 composed of volcanic material, and limestone, succeeded by mas- 

 sive, hard, blue limestone. Most of the corals occur in the lower 

 part of the sedimentary formation, in the limestone or in the 

 softer, more rapidly weathering layers of calcareous sandstone, in 

 which there is rehandled volcanic material. In conglomerate at 

 the base of one exposure I observed boulders of volcanic material 

 as much as 8 inches in diameter. Although, as Cleve stated, there is 

 some interbedding of the limestone and agglomerate in the lower part 

 of the sediments the upper formation rests unconformably on the 

 lower. 



The gradation upward into purer, more massive limestone has been 

 mentioned. The presence in the higher limestone of a few corals of 

 the same species as those in the lower beds and the abundance of 

 calcareous algae in some places, indicate a shoal-water deposit; 

 and, as the area of the deposit is relatively extensive, the evidence 

 is in favor of its having been laid down on a submerged flat. 



The Jamaican Eocene corals are shoal-water forms but they are 

 really not of reef facies. 



WEST INDIAN MIDDLE OLIGOCENE REEFS. 



ANTIGUA. 



That the bedded volcanic tuffs underlying most of the Central 

 Plain of Antigua dip under the Antigua formation toward the north- 

 east is indicated by the general structure of the island, and is con- 

 firmed by a well record, kindly furnished me by Dr. H. A. Tempany, 

 government chemist of the Leeward Islands. The record mentioned 

 is of a well bored on Fitches Creek, half a mUe northeast of the south- 

 west boundary of the limestone. Compact, noncalcareous rock 

 was struck below the limestone. In the Central Plain patches of 



1 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. 



