Vol. 67.] OF ANTIGUA AND OTHER WEST INDIAN ISLANDS. 



683 



The north-eastern region consists mainly of a calcareous formation 

 called by Dr. Spencer the Antigua Formation. He identifies with it 

 the White Limestone of Barbuda, St. Martin, and Guadeloupe, and 

 calls it ' Oligocene.' It is generally a chalky rock, varying much in 

 hardness and coherence, and containing numerous casts of mollusca 

 and other fossils. At a marl-pit about 2 miles from St. John, to 

 which Mr. Forrest took me, I found this rock to contain many 

 fossils, one of which was a Pholadomya : there were also casts of 

 a Turritella. This rock was full of small Orbitoides. I did not 

 detect other foraminifera or radiolaria. Proceeding to Hodge's Bay 

 on the north of the island, we found a similar rock exposed on the 



Fig. 1. — Outline-map of 'Antigua, to sliow the inlets, etc. 

 on the scale of 6 miles to the inch. 





shore, and containing Orbitoides measuring between 2 and 3 inches 

 in diameter, and many Pectens ; but we failed to extract entire 

 specimens. The large size and peculiar condition of the Orbitoides 

 made me somewhat doubtful about them, and my workshop and 

 library not being at hand I could not verify the determination ; 

 but afterwards Dr. Lang, of the British Museum (Natural History), 

 was good enough to examine them and to give me his opinion that 

 they were truly Orbitoides (mantellii) as previously determined by 

 the late Prof. T. llupert Jones. Some portions of this rock were 

 almost entirely composed of the smaller Orbitoides, being in this 

 respect quite similar to the Orbitoides Bed of Naparima (Trinidad), 

 Q. J. G. S. No. 268. 3 4 



