Vol. 58. | PHYSICAL DEVELOPMENT OF BARBADOS, ELC. ot aes 
But this rise of the land to over 1000 feet is greater than that traced 
in other islands. Indeed, the amplitude of all the more recent 
changes of land appears to have been greater in the south than in 
the north. The subject of the calcareous formations deserves still 
further investigation. 
IX. Noves on THE Puysicat FEATURES OF TRINIDAD. 
The greater part of Trinidad consists of undulating plains rising 
to 200 feet above the sea, with some extensive swamps. Along the 
southern and the eastern coasts are a few isolated hills, as also a 
range of hills in the interior, whose summits reach more than 1000 
feet above sea-level. But along the northern side of the island is 
a range of mountains containing crystalline schists, etc., which 
culminate in points 3100 feet above the sea. Various formations 
of sandstone, shales, and calcareous rocks, in more or less disturbed 
strata, have been described by Messrs. Wall, Sawkins, and Guppy, 
the last-named of whom places the highest of the series (Caroni) as 
the equivalent of the Lower Miocene of Jamaica,’ now referred to 
the Oligocene Period. Accordingly, the entire topographic outlines 
of the lower country are due to the sculpturing of the surface 
during the Miocene-Pliocene Period, as it has been re-covered by 
newer formations to only a limited extent. At Matura Bay, on the 
eastern coast, Mr. Guppy found a deposit with shells, which he 
regarded as indicating a Newer Pliocene Period. I was unable to 
visit the locality, but I suspect that in some way this formation 
will be found to correspond in time with the Bath Series of Barbados 
—that is, the early Pleistocene Period. 
Superficial eravel- deposits have been mentioned by previous 
writers. Some of these deposits I have visited: thus, behind St. Joseph 
are terraces at 110, 135, 185, and 210 feet above the sea. That 
at an elevation of 185 feet was covered by a layer containing 
numerous shells of Strombus, oysters, etc. These terraces are com- 
posed of loam and gravel, only part of which is rounded and part is 
subangular. The colour is reddish or brownish. The plains of the 
Caroni are covered with the same material, but contain few pebbles. 
Along Dry River (near Port-of-Spain), the surface is covered by 
10 or 12 feet of red loam, overlying 3 or 4 feet of well-rounded 
gravel. South of San Fernando are extensive horizontal beds of 
sand and loam, with some pebbles, resting upon the upturned strata 
of the older formations. These have a thickness of 50 feet. They 
do not belong to the same formation as the terraces just mentioned. 
Mr. Wall classified them provisionally with the later deposits of a 
Tertiary formation, at the same time asking whether they were really 
such. In position they appear to be a post-Miocene-Pliocene 
accumulation, subsequent to the denudation of that long period. 
At the point where the Arima River leaves the northern mountains 
is an old base-level flat at 200 feet above the town, or about 400 feet 
above the sea. This flat is deeply dissected by the stream, in such 
‘In his earlier papers Mr. Guppy placed the Caroni Series in the Upper 
Miocene, Quart. Journ. Geol. Soe. vol. xxii.(1866) p. 572. 
