362 PROF. SPENCER ON THE GEOLOGICAL AND [Aug. 1902, 
cene (?) Formation, which itself has suffered greatly from erosion. 
Remnants of this massive coral-rock occur in the Scotland Valley 
and at other points. . 
Without entering into the question of what terraces are due to 
marine erosion, leaving sea-cliffs in the rear of them, and what are 
constructional from the building-up of reefs, it may be said that 
these deposits of recent coral-species are widespread over the 
surface, not merely below the altitude of 165 feet, but possibly (in 
part at least) at the higher levels, where pockets of coral-masses con- 
taining recent species occur. Some of these, however, may belong to 
an even later epoch of the Pleistocene Period than the Bath Series. 
As noticed at Bath, the series rests upon a mechanical foundation : 
although unconformity is suggested, it may possibly be its lowest 
member. At other points, at the same or lower levels, the over- 
lying coral-formation is wanting where it should be found. This 
emphasizes the subsequent denudation. But in Dominica, the cor- 
responding coral-formation rests in hollows upon the surface of 
gravels. At any rate, great denudation of the surface of the Bath 
Series occurred during the epoch of the elevation of the land, when 
the deep valleys and cirques indenting the margins of the Antillean 
Plateau were completed. These features are illustrated in a small 
degree in the Scotland Valley and adjacent off-shore soundings 
shown, though they could not be strongly marked by the incomplete 
soundings of the steep submarine slopes (almost without a fringe) 
of this outlying Barbadian remnant of the Antillean Plateau. But 
deep erosion-features are illustrated in the submerged ravines or 
cirques at the mouth of the Gulf of Paria, and between Trinidad 
and Tobago. 
The study of the relationship of the Bath Coral-Reef and the 
mechanical deposits will help us to understand the whole West 
Indian Series, forming, as they do, mantles of similar thickness and 
characteristics in Grand’ Terre (Guadeloupe), Anguilla, Tintamarre 
(near St. Martin), St. Kitts, Sombrero, and Dominica. Whether or 
not the coral-reefs in the various islands, with a similar fauna 
and development, be nearly as old as the Mechanical Marls, which 
are regarded as the equivalent of the Lafayette Formation of the 
North American continent (provisionally assigned to the close of 
the Pliocene Period), it is certain that they cannot be much older, 
if quite so old, as the early Pleistocene Period; yet they were 
anterior to the epoch of great elevation of the land, when the 
deep gorges and cirques were being completed. As there is no 
paleontological guide in separating the various episodes of the 
Pleistocene Period, one is quite prepared to learn that some of the 
coral-deposits, newer than the lower gravels, may belong to a little 
later date than the Bath Series. Thus some of the newer coral- 
accumulations were probably formed during the subsidence, when 
the waves carved out the sea-cliffs of the higher terraces of 
Barbados. This subsidence would correspond in time with that 
of the Columbia Formation of other islands and the North 
American continent. As the terraces are dissected by only youthful 
ravines, the re-elevation must have been comparatively recent. 
