f 



72 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



the Orbitoidal flints from St. Mary collected by Wall have been studied 

 by T. Rupert Jones, and published in the Geological Magazine/ as 

 further commented upon in the paleontologic portion of our paper. Our 

 studies enable us to show the exact geological position of these speci- 

 mens, which has been hitherto unknown. The Orbitoides are quite 

 large, and can be collected usually in close proximity to the flints some- 

 times attached to them. They closely resemble the forms so abundant 

 in the yellow marls of the Chapelton formation and may be specifically 

 identical. 



Under the microscope the entire mass of most of the chalks collected 

 by us consists of Globigerinse, which at present form great deposits on 

 the ocean's bottom between 1,500 and 2,900 fathoms. The specimens 

 collected from Montpelier Hill, the foothills north of Savanna-la- Mar, 

 Dover, between Annatto Bay and Buff Bay, St. Margaret, and near 

 Buff Bay, — widely separated localities, — were entirely made up of 

 Globigei'inae. 



The Montpelier beds are best exposed in the hills of the north side of 

 the island in the bluffs of the back coast country along the north coast 

 road, notably near St. Ann, Falmouth, and Montego Bay ; from Port 

 Antonio westward into Hanover Parish ; and typically along the line 

 of the Jamaican railway between Montpelier to Montego Bay, and at 

 many other places around the island. They are exposed almost con- 

 tinuously across the island in the parishes of Westmoreland and 

 Hanover, between Anglesea near the coast, five miles east of Savanna-la- 

 Mar, and Montego Bay via Montpelier, where they have been well 

 described by Charles B. Brown under the name of " White Limestone," 

 as previously mentioned. Here they constitute most of the uplands or 

 hills of the back coast country, except where eroded through in the 

 processes attending the making of the sinkhole and cockpit countries. 

 In the valley in which Montpelier is situated, and also that near the 

 heads of Thicket and Morgan Rivers, many peculiar isolated buttes 

 standing upon a floor of Cambridge and Richmond beds are made up of 

 the Montpelier limestones; also the railway cuts between Montego Bay 

 and Montpelier are composed of them. 



They are repeatedly exposed in great thickness along the front of the 

 back coast hills along the coast road from Montego Bay to St. Margaret 

 Bay east of Port Antonio. At Cinnamon Hill (St. James) the beds are 

 almost vertical, inclining to the north coast. Here the limestone of 

 homogenous texture is in thin evenly bedded layers at the base, suc- 



1 Quart. Jour. Geol. Soc. London, 1864, Vol. XIV., foot-note page 104. 



