82 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



and below the May Pen formation. Its relations with the Bowden 

 beds of our section are not established. It apparently occupies an in- 

 termediate position between the Moneague and the Bowden. 



The Coastal Series. 



Older Portion. — The Bowden and Allied Formations^ 



This series includes a class of formations which represent the products 

 of events more recent in the history of the Jamaican sequence than 

 those hitherto enumerated. Its members occur around the coastal perim- 

 eter of the island, principally along the margins of the sea at altitudes 

 nowliere exceeding 250 feet, and deposited unconformably against the 

 sides of an older mainland. Here and there on the south coast they 

 fill previously formed erosion plains. They were all made during epochs 

 subsequent to an epoch of elevation whereby the white limestones of 

 the Oceanic Series and all preceding formations had been elevated into 

 land, had undergone tremendous denudation, and had again suffered 

 partial marginal subsidence. 



They are of four types of formations, to wit : beds of impure marine 

 limestone, gravel, and marl ; alluvium of the Kingston type ; elevated 

 coral reefs as illustrated in the Barbican and Hopewell formations; and 

 littoral deposits of calcareous mud, with embedded fossils of contempo- 

 raneous origin with the elevated reef formation. The four types in 

 their general lithologic characters are analogous to the marine littoral, 

 alluvial, and coral reef formations now being made around the margins 

 of Jamaica. 



21ie Boivden Bcds.^ — The Bowden and allied formations of later Ter- 

 tiary age constitute the older beds of the Coastal Series and are all 

 marginal to tlie main upland mass of the island. They apparenth' rep- 

 resent a series of fringing formations extending around the older Plateau 

 region. These in turn are bordered by still later and lower lying 

 formations. 



Along the south coast of the cast cud of tlie island, between Morant 

 Bay and Port !Morant, there is an extensive occurrence of gravel beds 

 less tliau 50 feet in thickness, containing rolled specimens of nearly 

 every species of volcanic rock found in the island, which grades up- 

 wards into an impuni stratified brown and buff colored marl, the latter 



1 The " Yellow Limestone" of Etlieridire. Wall. Jones, Woodward, and others; 

 not the " Yi'Ilow Limestone" of J^awkins and Brown. 

 ^ Tills name is adapted from Dall. 



