Trans. N. Y. Ac. Sez. . 22 Nov. 7, 
phic limestone, occasionally with recognizable fossils, sufficient to fix 
the age as certainly Cretaceous. 
Santa Cruz Island is then described, and referred to the same series 
as the Virgin group. All these islands thus indicate, by their east and 
west strike, and the great up-turning of their rocks, that they were 
formed by a north and south pressure, forcing the Cretaceous and asso- 
ciated volcanic beds into a great line of anticlinal and synclinal folds. 
This period seems to have been about that of the white Chalk; but tre 
force continued to act during the succeeding Eocene time, though with 
diminishing intensity, as is shown by the less inclination of the Eocene 
beds. The Miocene strata are little disturbed, and the force would 
therefore seem to have spent itself by that period. = 
Prof. Cleve then refers briefly to the occurrence of similar metamor- 
phic and volcanic rocks in the interior of the Great Antilles, and re- 
gards the entire series as having been formed by the same general 
movement of Cretaceous folding, the Virgin Islands forming the east- 
ern extension of the line of elevation. \ 
The Eocene strata are then taken up and discussed, as they occur in 
the islands of St. Martin and St. Bartholomew, just east ot the Virgin 
group. Professor Cleve regards these islands as wholly of Eocene age, 
claiming that the eruptive rocks, of which they mainly consist, are 
enterstratified with the limestones, which contain fossils of the age of 
the Calcaire Grossier, of the Eocene of Paris. He then traces the 
occurrence of Eocene strata in Antigua, Guadaloupe, parts of Trinidad, 
and largely in Jamaica; and re-affirms his conclusion that the move- 
ment which raised the Great Antilles and the Virgin islands continued 
during the early Tertiary, though with lessening force. 
The Miocene formation 1s then considered. It forms the small 
island of Anguilla, and occurs on several of the islands, south to Trin- 
idad ; but has immense development in the Great Antilles. It 1s chiefly 
a limestone series, is generally little disturbed from a horizontal position, 
and at times may be seen resting unconformably on the Eocene. By 
this time, evidently, the disturbing movements had ceased to make 
themselves felt. 
The later Tertiary rocks, Pliocene and Post-pliocene, have not been 
very clearly marked off from each other or from the Miocene. But to 
the Post-pliocene period are referred the Bahamas, Anegada, and the 
remarkable series of volcanic outbreaks that characterize the islands of 
Saba, St. Eustatius, St. Kitts, Nevis, Monserrat, Guadaloupe, &c. On 
St. Kitts, Prof. Cleve describes a limestone with over forty species of 
fossil shells, all but one of which are identified with living species of 
the Caribbean ser. The same is true of Anegada. 
The elevation of the Miocene strata of the Great Antilles took place 
