176 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



In the islands of Antigua, Guadeloupe, and Martinique, of the Wind- 

 ward Island group, which are quite different in generic structural 

 character from the Antilles and ^.■^irgin Islands, there are vast deposits 

 of stratified tuffs which belong to several epochs. The lower portions 

 of these are suggestively like the Richmond beds in arrangement, al- 

 though entirely different in composition. We are not prepared, how- 

 ever, to assert their identity at present, although there is some evidence 

 of synchronous origin, as some of them in Antigua clearly underlie 

 fossiliferous beds similar to those elsewhere overlying the Richmond. 

 The whole structure of the island of Barbados below the veneering of 

 reef rock is composed of an intensely folded land-derived formation of 

 littoral land-derived shales and sandstones (the Scotland beds) which 

 closely resemble the Richmond Eocene formation of Jamaica and the 

 other localities mentioned, and in our opinion is identical in age with 

 them, as will be shown in a future paper. 



The widely distributed occurrence of such beds of land-derived 

 material at the base of the Tertiary in the Great Antilles and Barbados, 

 is suggestive of the existence and destruction of extensive land areas 

 concerning which I can now state but little. Furthermore, these forma- 

 tions are remarkably similar in general character to the synchronous 

 deposits of the continental littoral, as will now be shown. 



Along the continental margins of North, Central, and South America 

 there are thick formations of approximately synchronous age which have 

 a remarkable and suggestive lithologic and structural resemblance to 

 the Richmond beds of the Antilles, being composed like them of im- 

 pure unwashed land derived material accompanied by plant remains and 

 bituminous matei'ial, everywhere occurring in uniform wide extending 

 alternations of sands and clays indicative of shallow marginal deposition 

 within the limits of tidal action, and marked by the absence of lime- 

 stones of organic, oceanic, or other than segregational secondary origin. 

 Of this nature are the lower and by far the greater portion of the 

 Eocene beds of the Southern Coastal Plain of the United States, — 

 the Great Northern Lignite Group of Hilgard, — which extends as far 

 southward as the Tropic of Cancer in ^[exico, and the similar forma- 

 tions which characterize the closing days of the Cretaceous and begin- 

 ning of the Tertiary throughout the great Rocky Mountain front. The 

 lithologic resemblance of the older Tertiaries of the Central American, 

 Isthmian, and Colombian coasts of South America to those of the An- 

 tilles is equally striking. In Trinidad and Venezuela the Eocene for- 

 mation is also represented by a land-derived formation, the Naparima 



