170 BULLETIN: MUSEUM OF COMPAEATIYE ZOOLOGY. 



rocks in the West Indies, and while we are willing to grant that tliey 

 may have occurred, their exposure has been so completely covered by 

 the more recent events «f sedimentation, vulcanism, and diastrophism 

 that the interpretable history of the islands may be said to commence 

 with Cretaceous time. The rocks and general section of the Great 

 Antilles all present otherwise a great resemblance to those of Jamaica, 

 as will now be shown. 



Clastic rocks composed of water deposited tuffs and volcanic debris, 

 with occasional Cretaceous fossils of the type of the Blue Mountain 

 Series, constitute the basement formation of the interpretable geologic 

 series in all the Great Antilles as in Jamaica, and form the summit 

 masses of high mountain topography, showing that the present con- 

 figuration at least has largely been produced since the Cretaceous 

 period. 



Rocks of the character of the Blue Mountain Series, which constitute 

 the fundamental formations of Jamaica, have wide occurrence through- 

 out the other Great Antilles, Cuba, San Domingo, and Porto Rico, 

 and the Virgin Islands of St. Thomas, St. John, Tortola, Tost Vandyck, 

 Sandy Key, Guana, Caraanoe, Scrub, Mosquito, Prickly Pear, St. James, 

 Dog, Savanna, and Inside Bras ; also on the islands of St. Croix and 

 St. Bartholomew,-^ where they constitute the oldest rocks. In some of 

 these localities these rocks of the clastic basement group have not been 

 separated from the overlying Richmond and Cambridge formations. 



In Cuba these clastic rocks constitute the high divides of the Oriente, 

 and occur to the westward below the limestones in insular spots as 

 in Jamaica. In addition to the hornblende-andesite gravel which pre- 

 dominates in Jamaica, the Cuban and San Domingo beds contain debris 

 of the older rocks not found in Jamaica. 



In the Republic of San Domingo^ formations analogous to the Blue 



1 Geology of the Northeastern West Indian Islands. By P. T. Cleve. Stock- 

 holm, 187L 



- Tiie geology of the island of Haiti or San Domingo has been partially 

 studied by several geologists. These studies have been largely confined to the 

 eastern Republic of San Domingo. So far as we are aware, there is hardly a 

 single published contribution to tlie geology of the western Republic of Haiti. We 

 have in our possession, however, some important unpublished minor manuscripts 

 by Gabb. 



Those who have made researches of the island since 1804 were Schomburgk 

 (1851), Don Manuel Fernandez de Castro (during the Spanish annexation), Hen- 

 neken (about 1859), Prof. Gabb (about 1870), and the geologists of the United 

 States Commission, W. P. Blake, J. S. Adams, and A. R. Marvine (1871), and L. 

 Gentil Tiipenhauer. Of these it may be .said that the researches of Schomburgk, 



