hill: geology of Jamaica. 129 



T. W. Stanton of the United States Geological Survey has kindly 

 furnished the following determinations of the MoUusca collected by 

 me; — 



(a) From near Catadupa : — Ostrea, sp. ; resembles young of 0. cora- 

 pressirostra. Carolia jamaicensis, Dall ; this is an Eocene genus. Ca- 

 prinula gigantea, Whitf.^ 1 ; a fragment. Caprinella occidentalis, Whitf.^ ; 

 a small specimen. Caprina jamaicensis, AVhitf.^ j several small speci- 

 mens. Radiolites rudis, Whitf.^; four specimens (lower valves) that 

 seem to belong to this species. Eadiolites adherens, Whitf.^ % ; one speci- 

 men doubtfully referred here. Radiolites, sp. ; several fragments of a 

 small strongly plicate species that cannot be satisfactorily identified 

 with any of those described by Whitfield. Caridum, sp. ; rather large 

 form. JSTatica, sp. ; casts. Nerita, sp. ; a medium sized smooth form. 

 Cerithium, sp. ; 1, Cerithium, sp. ; 2, fragmentary cast of very large 

 species. Thalassa ? sp. ; a Purpuroid shell resembling this genus, rep- 

 resented by a fragment. Cyprsea, sp. 



(2) From the Railway Cuttings at Cambridge. 



The collection from Cambridge is not so large, but it contains enough 

 identical species (marked *) to show that the same horizons are repre- 

 sented as at Catadupa. 



(6) From near Cambridge : — *Ostrea, sp. Anomia, sp. .*Carolia ja- 

 maicensis, Dall. Spondylidse C?) genus undetermined ; a peculiar shell 

 having the form of an Ostrea and resembling a Chama in sculpture 

 and shell structure. *Radiolites rudis, Whitf. 1 a single small speci- 

 men. Protocardia, sp. Cardium, sp. Lucina, sp. ; large casts. Merita, 

 sp. Cerithium, sp. ; a very large form resembling one of the huge species 

 from the Paris Basin Eocene. 



Several other indeterminate casts of bivalves and gastropods. The 

 genus Cassis w^as also identfied from the Cambridge collection by Dall. 

 A fragrnent of a Nerinsea also occurs. 



Chapelton Beds. — The upper beds at Chapelton are of later and 

 slightly deeper water origin than the Catadupa, and mark a stage in 

 the great Eo-Oligocene subsidence and a transition between the Cam- 

 bridge and Montpelier. They are characterized by the same little 

 Alectryonate oyster, large Cerithium and Lucina, which are found 

 at Cambridge. Several large Echinoderms occur in this horizon. None 

 of the other fossils of the Catadupa beds were noticed by us, while 

 a species of Orbitoides (the species referred to 0. mantelli throughout 



1 Forms hitherto supposed to have been peculiar to the Cretaceous beds of 

 Jamaica. 



VOL. XXXIV. 9 



