170 BULLETIN: MUSEUM OF COMPARATIVE ZOÖLOGY. 
rocks in the West Indies, and while we are willing to grant that they 
may have occurred, their exposure has been $0 completely covered by 
the more recent events ef sedimentation, vuleanism, 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 geologi¢ 
series in all the Great Antilles as in Jamaica, and form the summit 
masses of high mountain topography, showing that the present cor- 
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, Lost Vandyck, 
Sandy Key, Guana, Camanoe, 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 g 
these localities these rocks of the clastic basement group have not bee? 
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 i 
in Jamaica. In addition to the homblende-andesite gravel which Pp!” 
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, 1871. 
2 The geology of the island of Haiti or San Domingo has been partially 
studied by several geologists. 'These studies have been largely confined to th? 
eastern Republic of San Domingo. So far as we are aware, there is hardly * 
single published contribution to the geology of the western Republic of Haiti. we 
have in our possession, however, some important unpublished minor manuscript 
by Gabb, 
m k 
Those who have made researches of the island since 1804 were Schone 
)» 
neken (about 1859), Prof. Gabb (about 1870), and the geologists of the Unit 
