140 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



tests of Orbitoides, Alveolina?, and MiliolidEe, while the interior mass of 

 one flint clearly shows the silicified outlines of these remains. 

 Concerning these species Bagg comments as follows : — 



"The limestones and flints with numerous Orbitoides must belong to the 

 Eocene period, because this genus Orbitoides though sparingly found in Upper 

 Cretaceous beds did not become prominent until Eocene time, and, further- 

 more, it did not survive the Miocene age and only a few occur in the Miocene. 

 Its geologic range is as limited as almost any other single genus in the 

 Foraminifera group. 



" The species of Orbitoides called dispansus, Sowerby, is easily recognized 

 by its internal structure and its external mammillated surface. This species 

 is one of the essential constituents of the Eocene rocks of Scinde and also 

 occurs in the Eocene of Southern Germany and Italy. 



" ISTummulites is another genus almost equally important, being limited in 

 range to the Tertiary period and rarely found now. We have lately dis- 

 covered this genus in the Eocene beds of Vicksburg, Mississippi. 



" The Globigerina limestones of which 486 is a good example, are fine 

 illustrations of a rock composed almost entirely of these microscopic organisms. 

 It is, however, impossible to state with certainty its age upon this occurrence. 

 Since Globigerina cretacea seems to be absent from these limestones w^e pre- 

 sume the rock is to be placed in the Tertiary period." 



Nnramulinae, so characteristic of the Eocene of Europe and North 

 i\frica, but missing in the Eocene of the United States, except in the 

 Vicksburg formation of Florida and Mississippi, where they have 

 recently been identified by Bagg, have been noted in Jamaica, first by 

 De la Beche, next by Woodward, and more fully identified by T. 

 Rupert Jones,^ supposedly from the Orbitoidal beds, in association with 

 Orbitoides, and also in the flint bearing beds of the Montpelier forma- 

 tion, which erroneously, as in the case of Orbitoides, owing to the 

 stratigraphic misconception, were referred by Jones^ and Guppy to the 

 Miocene. Operculinae are also reported by Jones in the flint of Preston, 

 St. Mary, and Brimmer Hill, associated with Nummuliuse, characteristic 

 localities of the Montpelier beds. 



In two papers, Prof. Jones' describes the material and gives the 

 localities of certain specimens sent from Jamaica in a manner that, after 

 our personal studies of the island, we found no difficulty in recognizing 



1 See papers of these authors previously cited. 



2 Geol. Magazine, London, 1864, Vol. I. pp. 102, 106. 



^ The Relationship of Certain West Indies and Maltan Strata, etc., by T. Rupert 

 Jones. The Geologist, January, 1804, Vol. VII. No. 73, pp. 104, 105. 



