ART. 14 PORAMIISriFEEA FROM TRINIDAD — CUSHMAN AND JAEVIS 9 



AMMODISCUS PENNYI Cushman and Jarvis 



Plate 2, Figxires 2. 3 



Animodisous pennyi Cushman and Jabvis, Coutr. Cushman Lab. Foram. Res., 

 vol. 4, p. 87, pi. 12, figs. 4, 5, 1928. 



Test planispiral, comparatively large, periphery broadly rounded, 

 of a few coils, the tubular chamber increasing gradually in diameter ; 

 suture deep and distinct; wall thick, conspicuously arenaceous but 

 fairly smoothly finished; aperture semicircular at the end of the 

 tube. 



This is one of the largest species of the genus and is represented 

 by both megalospheric and microspheric specimens. In contrast with 

 the preceding species, the wall is very thick and has much arena- 

 ceous material. It occurs in the pit at Lizard Springs, as well as at 

 a depth of Y20 feet. 



Genus AMMODISCOIDES Cushman, 1909 



AMMODISCOIDES TURBINATUS Cushman 



Plate 2, Figures 4, 5 



Ammodiscoides turWnatus Cushman, Proc. U. S. Nat. Mus., vol. 36, p. 424, pi. 

 33, figs. 1-6, 1909; U. S. Nat. Mus. Bull. 104, pt. 1, p. 98, pi. 36, figs. 3-6, 

 pi. 37, 1918.— Rhumbler, Foraminifera of the Plankton-Expedition, pt. 2, 

 p. 388, figs. 124 a. d (in text), 1913. 



The Cretaceous material referred to this species has been very care- 

 fully compared with the types in Kecent dredgings, and there are no 

 characters by which they may be separated. Except for the differ- 

 ences due to fossilization, it would be impossible to tell the fossil 

 and Kecent specimens apart if they were mixed. This seems to be 

 an excellent example of the persistence of a species over a long 

 period where unchanged ecologic conditions have prevailed. 



The early whorls form a low cone on one side, and on the opposite 

 side a distinct depression, after which the succeeding coils are prac- 

 tically in a single plane. The genus is already known from the 

 Paleozoic and Recent collections, and this Cretaceous one is inter- 

 esting as partially filling the gap between these. This species was 

 originally described from dredgings in the Gulf of Mexico, so that 

 it has persisted under similar conditions since the Cretaceous at least. 



Genus GLOMOSPIRA Rzehak, 1888 



GLOMOSPIRA GORDIALIS (Jones and Parker) 



Plate 2, Figures 6, 7 



Trochammina squamata var. gordialis Jones and Parkek, Quart. Journ. Geol. 

 Soc, vol. 16, p. 304, 1860. — Parker and Jones, Philos. Trans., vol. 155, p. 

 408, pi. 15, fig. 82, 1865. 



