ABT. 14 FOEAMINIFERA FROM TRINIDAD — CUSHMAN AND JAKVIS 25 



iiig in breadth as added but with the height remaining nearly the 

 same throughout, the later ones becoming much elongate; sutures 

 limbate, in the early portion raised and somewhat irregularly beaded, 

 later becoming entirely so, and in the last-formed portion even slightly 

 depressed; wall, except for the umbilicus, which is beaded, and the 

 raised sutures, smooth; aperture at the peripheral angle, radiate. 

 Length, 5; breadth, 3; thickness, in the umbonal region, 0.9, at the 

 middle of the last-formed chamber, 0.35 mm. 



Holotype.—\5.^.'^M. No. 73824 (Cushman Coll. No. 15317), from 

 Upper Cretaceous of pit at Lizard Springs near Guayaguayare, 

 southeastern Trinidad, British West Indies. 



Remarks. — This is a large and striking species with a distinctive 

 ornamentation. The greatest breadth is formed early in the develop- 

 ment of the test in the umbonal region, after which it becomes 

 complanate and much thinner. 



Genus MARGINULINA d'Orbigny, 1826 



MARGINULINA GRATA (Reuss) 



Plate 7, Figxjbes 7 a, b ; Plate 8, Figures 3 a, 6 



Cristellaria grata Reuss, Sitz. Akad. Wiss. Wien, vol. 46, pt. 1, p. 70, pi. 7, figs. 



14 a, b, 1862 (1863).— Cushman, Bull. Amer. Assoc. Petr. Geol., vol. 10, 



p. 598, pi. 19, figs. 1 a, b, 1926. 

 Lenticulina grata Cushman and Jarvis, Contr. Cushman Lab. Foram. Res., 



vol. 4, p. 96, pi. 14, fig. 3, 1928. 



Test elongate, compressed, periphery rounded; chambers distinct, 

 the early ones coiled, later ones uncoiling, of rather uniform shape 

 increasing slightly in size and height as added; sutures distinct, 

 limbate, flush with the surface, gently curved; wall smooth; aperture 

 radiate, at the peripheral margin. Length, 1.1-1.2; breadth, 0.3-0.4; 

 thickness, 0.2-0.25 mm. 



This is a common Upper Cretaceous species known from numerous 

 localities in Europe and widely distributed in America. 



MARGINULINA MULTISEPTATA (Reuss) 



Plate 8, Figures 4 a, 6 



Cristellaria multiseptata Reuss, Haidinger's Natnrw. Abh., vol. 4, pt. 1, p. 33, 

 pi. 2, fig. 9, 1851; Deukscln-. Akad. Wiss. Wien, vol. 25, p. 147, pi. 3, figs. 

 14, 15, 1865. 



Test longer than broad, periphery subacute, later portion uncoiling ; 

 chambers fairly distinct, very slightly if at all inflated; sutures 

 distinct, flush with the surface, slightly curved; wall smooth; aper- 

 ture radiate, at the peripheral margin. Length, 1.2-1.4; breadth, 

 0.6-0.75 ; thickness, 0.35-0.4 mm. 



