70 GEOLOGY AND PALEONTOLOGY OF THE WEST INDIES. 



Orbiculina adunca (Fichtel and Moll). 



Orbiculina adunca (Fichtel and Moll) d'Orbigny in De la Sagra, Hist. Fis. Pol. Nat. Cuba, 

 "Foraminiferes," p. 64, plate 8, figs. 8 to 16, 1839. 



Specimens of this common West Indian species occur at Zones H 

 and I, Rio Cana, and Bluffs 2 and 3, Cercado de Mao, Santo Domingo. 



Orbiculina compressa d'Orbigny. 

 (Plate 7, Figure 6.) 



Orbiculina compressa d'Orbigny, in De la Sagra, Hist. Fis. Pol. Nat. Cuba, "Foraminiferes," 

 p. 66, plate 8, figs. 4 to 7, 1839; Jones, Parker, and H. B. Brady, Crag Foram., Pal. 

 Soc, vol. 19, p. 21, plate 3, fig. 43, 1866 ; Hill, Bull. Mus. Comp. Zool., vol. 34, p. 

 147, 1899. 



The following is a description of this species: 



Test flattened, circular or elliptical in outline, early chambers spiral, soon 

 extending back to make a crosier-formed test, after which by further elonga- 

 tions the chamber ends meet and form annuli; wall calcareous, smooth, aper- 

 tures circular openings about the peripheral wall. 



Diameter up to 3 mm. 



This species is not uncommon in the Bowden material from Jamaica, 

 but is frequently broken, due to the thin, entirely calcareous test and 

 the weakness that easily develops along the sutural lines. In Hill's 

 list of the species identified by Doctor Bagg both 0. compressa and 

 0. adunca are given. Among the specimens I have seen there is none 

 that is the typical thick form of 0. adunca; but all are thin, flattened, 

 and develop annuli very early, and, therefore, are typical 0. compressa. 



Orbitolites (Sorites) duplex Carpenter. 

 (Plate 5, Figures 9, 10.) 



The material from U. S. G. S. No. 6949, Simson Bay Point, St. Martin, 

 numerous specimens of a medium-sized Orbitolites. Vertical sections 

 of material from this station are shown on plate 5, figure 9. As a rule 

 the specimens are much like 0. duplex in section. According to 

 Douville, current conceptions of Orbitolites need much revision. The 

 true Orbitolites, with 0. complanata as the type, from the Eocene of the 

 Paris Basin, seems to be not found living at the present time. A 

 portion of a horizontal section from U. S. G. S. No. 6894, southwest 

 side of Crocus Bay, Anguilla, shows a few chambers in which the con- 

 nections between the adjacent" chambers seem much more like those in 

 Sorites Ehrenberg, which, according to Douville, includes the recent 

 species 0. marginata and 0. duplex. The fossil Orbitolites need a 

 careful revision from a study of carefully sectioned material. 



Specimens very similar to the above occur at the following stations 

 in Cuba, collected by T. W. Vaughan: 3440, northeast part of Santiago, 

 in marl on hillside; 3443, northeast part of Santiago, marl at foot of 

 hills, and 3446, first deep cutting on railroad east of La Cruz, near 

 Santiago. 



