AUT «= i ee 
Mem oe 
3500 PROF. SPENCER ON THE GEOLOGICAL AND [Aug. 1902, 
The foregoing species are all recent, except perhaps the Pecten. 
Mr. R. J. L. Guppy gave the following lists of corals and shells 
from one of these localities. They, too, are recent West-Indian 
species. He found also one or two unnamed species.! 
CorALs. 
Favia ananas, Lam. | Husmilia aspera. 
fF. coarctata, Mich. & Duch. { 
Motuvsca. 
Cyprea exanthema, Linn. | Neritina punctulata (!) Lam. 
C. cinerea, Linn. | Lurbo pica, Linn. 
Cassis decussatus, Linn. | Conus testudinarius, Mart. 
C. flammeus, Linn. | Spondylus coccineus, Lam. 
Purpura trapa, Bolt. _ Lucina tigria, Linn. 
Ranella cubaniana, dV Orb. | Tellina fausta, Sol. 
Triton pilearis, Linn. | T. interrupta, Wood. 
Dolium pennatum, Mart. | Pectunculus angulatus, Lam. 
Pusio articulatus, Lam., var. (?) [per- | Lithodomus cinnamomeus, Lam. 
haps a new species]. _ Petricola robusta, Sow. 
Natica mamilla, Linn. _ Plicatella cristata, Lam. 
N. canrena, Lam, 
These names have not been revised. Mr. Guppy classified the 
formation as Pliocene. 
The coral-tormation in Dominica has the same characteristics and 
about the same thickness as the Usine Beds at Pointe 4 Pitre (Guade- 
loupe), the upper marls of Anguilla, the limestones of Brimstone 
Hill (St. Kitts), and similar beds in Barbados, and also others in 
Sombrero. Owing to the modern aspect of the fauna, the age would 
appear to be Pleistocene, or not older than the close of 
the Pliocene, which last view may be favoured if measured by the 
subsequent great denudation to which the beds have been subjected. 
These coral-beds rest unconformably upon the lower gravels, thus 
showing that those deposits are of considerable age and belong to a 
period preceding the early Pleistocene great elevation and denudation. 
This occurrence would cause them to be referred to the Lafayette 
Formation of the American continent. Where the upper gravels lie 
unconformably upon the lower, the marls must have been removed 
before the deposition of the latter. It would appear that the 
upper gravels and the tufaceous earths overlying them, at Grand 
Savanna, and like accumulations covering the coral-beds at Coral 
Point, occupy the same position in Dominica as similar deposits in 
the other islands which have been referred to stages of the Columbia 
Formation of the American continent, or a mid-Pleistocene 
Series. The lava underlies at least the upper gravels, pointing 
to renewed volcanic action in the Pleistocene Period. 
VIL. Tur TEerraces. 
Morne Bruce is a terrace on the southern side of the Roseau 
Valley, with an elevation of about 400 feet. On the northern side 
1 Proc. Sci. Assoc. Trinidad, Dee. 1869, pp. 390-91. 
