598 BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



also to occur in northern Nicaragua. Sapper records Triassic rocks 

 from several areas in Honduras. 



Jurassic limestone froms the axis of the Organos Mountain, Province 

 of Pinar del Rio, Cuba; and marine Jurassic is extensively developed 

 in Mexico and west Texas. 



The Lower Cretaceous, so greatly developed in Mexico and Texas, 

 is not known in the West Indies or in Central America proper, that is, 

 below the Isthmus of Tehuantapec, except in Honduras. 1 



With regard to the Upper Cretaceous, it will be said that the pecul- 

 iar Upper Cretaceous fauna of Jamaica has been found in Cuba and 

 St. Thomas. Hill has noted in Porto Rico "volcanic tuffs and con- 

 glomerates with interbcdded Cretaceous rudistean limestone similar 

 to that of Jamaica," thereby confirming a previous inference of Cleve 

 that the horizon he recognized in St. Thomas also occurs in Porto 

 Rico; and it is reported from the Island of Haiti. Quin figures a 

 specimen of Barretiia from the "Blue-beach" formation of St. Croix 

 (but without recognizing its affinities); and Sapper records Barrettia 

 from northwest of Coban, Guatemala, and a somewhat similar fauna 

 from Chiapas, Mexico. As Cleve years ago pointed out, this fauna is 

 more closely related to that of Gosau, Austria, than to any in North 

 America north of the Gulf of Mexico. Hill reports Rudistes and 

 Inocerami from his San Miguel formation, Costa Rica, but Romanes 3 

 doubts the correctness of the identifications. 



OUTLINE OF THE GEOLOGIC HISTORY OF THE PERIMETERS OF THE 

 GULF OF MEXICO AND THE CARIBBEAN SEA. 



The following pages will present only the broad outlines of the 

 geologic history of the region of which Panama forms a part. The 

 details for Panama are given by Doctor MacDonald in the manu- 

 script of his report on the geology of the Canal Zone and adjacent 

 areas, to be published by the Smithsonian Institution. Three 

 manuscripts on the physiography and stratigraphy of Cuba are now 

 in my possession. One of these is on an area adjacent to Guanta- 

 namo, by Mr. O. E. Meinzer; the second is on an area northwest of 

 Guantanamo by Mr. N. H. Darton; and the third is a general ac- 

 count of the physiography and stratigraphy of the entire island and 

 the Isle of Pines by myself. The paleontology of the different forma- 

 tions is considered in as much detail as available information per- 

 mits. A similar account of the geology of the Lesser Antilles, by 

 Mr. Robert T. Hill and myself, is nearly ready for press, and pale- 

 ontologic monographs of the fossil biota of St. Bartholomew, Anti- 

 gua, and Anguilla are almost complete. The geologic history of these 



J Dr. T.W. Stanton has recentiy verified the age determination of these deposits. (Oral communi- 

 cation.) 



« Romanes, James, Geology of a part of Costa Rica, Geol. Soo. London Quart. Journ., vol. 63, pp. 103-139, 

 pis. 8, 9, 1912. 



