HILL: GEOLOGY OF JAMAICA. 177 



beds, which coincides in character with the Richmond formation of 

 Jamaica. 



The wide extent in latest Cretaceous and Eocene time of these impure 

 shallow water laud-derived deposits, so alike in sedimentary character, 

 is an evidence of changes of level during these epochs when rapid 

 erosion and deposition were going on. Around the continental margins, 

 except in Panama, the source of the material can be traced to an adja- 

 cent back land, but all geologic record of the lands whence the Antilleau 

 deposits came are destroyed. 



There is also evidence of wide occurrence in the Antilles of strati- 

 graphic horizons corresponding to the Cambridge beds of Jamaica, mark- 

 ing the rapid transition from the underlying land-derived shales into the 

 overlying Oceanic White Limestone deposits of the Montpelier type and 

 characterized by its peculiar invertebrate fauna. 



In the islands of Anguilla and St. Bartholomew the shales and con- 

 glomerates allied to the Richmond are overlain by or intercalated with 

 limestones and marl beds. The faunas of the two islands, as reported by 

 Cleve,^ are somewhat different. The fossils of these probable Eocene 

 horizons from Anguilla, as enumerated by Cleve, consist of many species 

 of molluscan genera, only one of which, Natica phasianelloides, W. J. G., 

 is also reported from the Richmond beds of Jamaica. These Anguilla 

 beds were originally referred to the Miocene by Guppy.^ Following the 

 latter author, Cleve, in describing the fossils, referred them to the 

 Miocene. This conclusion was fortified by the identity of the fossils 

 characteristic of the San Fernando beds of Trinidad, which Guppy at 

 that time also considered Miocene. Guppy in his latest papers has 

 referred the San Fernando beds, together with those of Anguilla,^ to the 

 Eocene, and the latter age must now be accepted for the Anguilla beds, 

 which are worthy of further investigation. 



In St. Bartholomew certain beds referred to the Eocene by Cleve * 

 and Guppy ^ have a most decided Cambridge aspect. Nearly every fos- 

 sil genus mentioned from them is identical with those found in the 

 Cambridge and Catadupa beds, including the peculiar gigantic Cerithium, 

 Terebratula, and the Echinoderms Macropneustes and Echinolampus, — 

 genera which were found by me in the Cambridge beds of Jamaica. 



1 Op. cit., pp. 22-26. 



2 Quart. Jour. Geol. Soc. London, 1866, Vol. XXIL p. 297. 

 s Geol. Magazine, London, September-October, 1874, p. 2. 

 * Op. cit., p. 44. 



5 Geol. Magazine, London, September-October, 1874, p. 2. 



VOL. XXXIV. 12 



