69 
Bibliographical Notices. 
ashes, seams of bitumen and springs of petroleum (Barbados tar). 
The coralline limestone occupies six-sevenths of the whole area of 
the island, and the author considers that the terraces it presents are 
owing to gradual elevation with intervening periods of rest and sub- 
sequent denudation, and gives a detailed account of the present con- 
dition and probable progress of the changes it has undergone. Casts 
of the shells of Turbo, Lucina and Petricola occur at the highest 
elevations of the coral rock ; the shells found eight hundred or a 
thousand feet lower still retain their lustre, but though resembling 
those of the adjacent seas, are usually much larger than the recent. 
The “Scotland” formation presents a very different appearance 
and structure from the coral ; the district in which it occurs is en- 
circled by a semicircular range of heights from which long ridges of 
hills project, converging towards each other and diminishing in height 
as they approach the sea. The various modifications of tertiary rocks 
of this district manifest an original uniformity, but present great signs 
of disturbance, and the stratification varies from horizontal to ver- 
tical, or is wavy or even contorted ; thus it is often difficult to ascer- 
tain the dip ; the direction is generally south-west and north-east. 
The earthy marl constitutes by far the greater part of this series, 
and it sometimes occurs stratified. It abounds in Polycystina : in 
the marl from Mount Hillaby Ehrenberg found 54 species, belonging 
to 22 genera ; another specimen gave 113 species of Polycystina with 
5 of Polygastrica, 1 Geolithia and 2 Phytolitharia. 'I'o the south 
the marl is succeeded by sandstones. The bituminous sandstones are 
intermixed with the more calcareous varieties. As to the age of these 
rocks, our author says, “ the Scalaria which I found on the summit of 
Bissex Hill and the JVwcM/aof Springfield, induced Prof. E. Forbes to 
consider the Scotland rocks as belonging to the miocene period of the 
tertiary strata. The mineralogical character of rocks is considered 
at present of little importance when conclusions respecting their age 
are to be formed. Still my observations on the spot, combined with 
the mineralogical character of the rocks, lead me to coincide in 
Prof. Forbes’s opinion. The chalks of Caltanisetta, on which Prof. 
Ehrenberg rests his opinion that the Scotland formation in Barbados 
belongs to an older period than the miocene group, have been con- 
sidered by different geologists as belonging to different periods ; by 
some they have been regarded as secondary, by others as tertiary 
rocks.” 
The whole Scotland district is apparently an old sea-bottom, and 
the author attributes its present disturbed condition to volcanic 
agency acting from given points and thus giving rise to local de- 
rangements. The presence of pumice and strata of volcanic ashes 
render this less doubtful, Isolated rocks of the coral formation are 
found lying on the summits and declivities of hills in the Scotland 
district ; these Sir Robert is inclined to regard as fragments detached 
from the cliffs Mffiich now border the district (and which, with the 
exception of Mount Hillaby, all exceed in height the “Scotland” 
hills), before the upheaval of the sea-bottom. 
A description of the fossils follows this chapter, containing an 
