I 



hill: geology of JAMAICA. 141 



their true stratigraphic position in the general section. This material 

 alid its occurrence as given by him is as follows : — 



1. In a piece of gray flint from the base of the White Limestone at 

 St. Thomas, Jamaica. Numerous Orbitoides, mostly 0. mantelli, though 

 some may be 0. dispansus. 



2. Orbitoidal limestone, Hopewell, Metcalf. Flint with Orbitoides 

 and Nummulinse, Orange River, Metcalf. 



3. Limestone with Operculinse and Nummulinse, and the same silici- 

 fied, Brimmer Hill, St. Mary. 



4. Flint with Operculinae and Nummulinse, Preston, St. Mary. 



5. Orbitoidal limestone, Carron Hall, St. Mary. 



6. Alveolina limestone. Crofts, Clarendon. 



7. Orbitulina rock, Vere. 



8. A specimen of hard yellowish limestone at Clarendon, largely 

 composed of the Heterosteginse, and further noted in this Part under 

 the head of Bowden beds. 



Of the above list Nos. 1, 2, 3, and 4 are undoubtedly from the flint 

 and chalk beds of the Montpelier formation ; No. 5 is probably from 

 the Cambridge beds ; No. 6 from the Moneague ; No. 7 comes most 

 probably from the Cobre limestone overlying the Bowden beds. 



From these collections, 1 to 5 inclusive, he identified 0. mantelli, 

 mixed with numerous forms referred to 0. dispansus and 0. fortissii, 

 associated with Nummulinse. Jones also says^ that the ''Orbitoides 

 mantelli of Morton, of stronger growth than the variety found in 

 Jamaica, Antigua, and Malta, characterizes some of the Tertiary beds 

 of Alabama, Nummulites being absent, it is supposed." ^ 



To this statement we might add that 0. mantelli is especially 

 characteristic of the Vicksburg horizon of the Upper Eocene (now 

 lower Oligocene of Dall) of the Southern United States, and has been 

 identified from this horizon by Dall from our collection from the beds 

 of this age in Costa Rica. According to Bagg, 0. fortissii, " a typical 

 Eocene form," also occurs in Panama lower down in the Eocene. 



Jones, accepting the current stratigraphic conceptions, was misled 

 into the serious error of concluding that these forms, notwithstanding 

 their world-wide habitat, w^ere Miocene in Jamaica. This opinion was 

 largel}'' due to the publications of J. Lechemere Guppy. 



Fossils of the Moneague Beds. — The limestones of the Moneague 

 beds abound in moulds of Mollusca. Fossils of this character from 



1 Loc. cit., p. 105. 



2 Since discovered by Bagg. Letter to author. 



