FORAMINIFERA OF THE ATLANTIC OCEAN 



41 



PENEROPUS DISCOIDEUS Flint 



Plate 15, figures 6-8 



Peneroplis pertusus (Forskal), var. discoideus Flint, Rep. U. S. Nat. Mus., 

 1897, (1899), p. 304, pi. 49, figs. 1, 2.— Cushman, Publ. 291, Carnegie 

 Instit. Washington, 1919, p. 69. 



Peneroplis discoideus Cushman, Proc. U. S. Nat. Mus., vol. 59, 1921, p. 76, 

 pi. 18, fig. 20; pi. 19, figs. 1-3; 13th Ann. Rep't Florida Geol. Survey, 

 1921, p. 63; Publ. 311, Carnegie Instit. Washington, 1922, p. 80. 



Test much compressed, in the young close coiled and involute, the 

 chambers later becoming elongate, finally spreading out and embracing 

 the earlier portion of the test, forming in the adult completely annular 

 chambers; sutures distinct, depressed; wall entirely smooth ; aperture 

 in the adult formed by pores about the median line of the periphery. 



Diameter, up to 2.25 mm. 



Flint described this species from shallow water of Key West Harbor, 

 Fla. I collected very typical specimens at this same locality, at the 

 Tortugas, off Jamaica and at Bermuda. It also occurs in the Baha- 

 mas and probably has a very wide general West Indian distribution. 

 It occurs also in the Late Tertiary of Cercado de Mao, Santo Domingo, 

 and in wells of southern Florida. 



There are no records of its occurrence in the Pacific, and like P. 

 proteus is probably a species of the western tropical Atlantic. 



It may be easily confused with Sorites compressa (d'Orbigny), 

 which may have developed from it. The Peneroplis, however, does 

 not have its chambers divided into chamberlets, a character easily 

 brought out by moistening the test. 



Peneroplis discoideus — Material examined 



