28 PROCEEDINGS OF THE NATIONAL MUSEUM vol.80 



terminal, radiate, with a slight neck. Length, 0.9-1; breadth, 

 0.35-0.6; thickness, 0.25-0.5 mm. 



This species, which is common in the Cretaceous of Europe, has 

 only been recorded in America from the Cretaceous of California. 

 Our specimens from Trinidad are somewhat more inflated, especially 

 in the later chambers, but the general characters of the species are 

 fairly constant. 



MARGINULINA DECORATA (Reuss) 



Plate 9, Fiqtjkes 2 a, h 



Cristellaria deoorata Reuss, Zeitschr. deutsch. geol. Ges., vol. 7, p. 209, pi. 8^ 

 fig. 16 ; pi. 9, figs. 1, 2, 1855. 



Test elongate, compressed, the periphery lobulate; early chambers 

 coiled, later ones uncoiled and becoming narrower as they are added ; 

 sutures distinct, limbate, raised, the earlier ones broken into a series 

 of beadlike projections, later ones nearly entire ; aperture somewhat 

 produced, at the peripheral angle. Length, 1.5-1.65; breadth, 0.6- 

 0.8; thickness, 0.5-0.6 mm. 



This is a somewhat variable species, but the figured specimens 

 seem to be close enough to Reuss's original types to be included under 

 his species. 



MARGINULINA TRILOBATA d'Orbigny 



Plate 9, Figures 3, 4 



Marginulina triloMta d'Orbigny, M^m. Soc. G6ol. France, s^r. 1, vol. 4, p. 16, 

 pi. 1, figs. 16, 17, 1840. 



Test elongate, the sides nearly parallel, periphery rounded ; cham- 

 bers distinct, rather uniform in size and shape; sutures distinct, lim- 

 bate ; the central portion at each side raised and thickened ; wall, ex- 

 cept for the sutural projections, smooth; aperture radiate, at the 

 peripheral margin. Length, up to 3.5; breadth, 0.7-0.8; thickness, 

 0.4-0.45 mm. 



The specimen figured is a megalospheric one and does not show the 

 early coiled chambers, which are much more apparent in micro- 

 spheric specimens. The raised sutures are somewhat variable in the 

 degree of thickening, but this character is usually present in consider- 

 able degree. The types of this species were described by d'Orbigny 

 from the Cretaceous chalks of the Paris Basin, and it is rather widely 

 distributed in the chalky phase of the Upper Cretaceous of Europe 

 and America. 



