331 Tertiary Foraminifera 37 



are all visible upon the superior side and separated by curved 

 band-like septa. Only faint irregular depressions of septal lobes 

 indicate the chambers of the final volution upon the inferior sur- 

 face. The septal lobes are not curved as upon the superior side; 

 aperture variable and sometimes invisible. Some forms show a 

 very small semi-lunar arch upon the lower surface. 



Diam., 0.52--0.65 mm. 



This little Pulvi?iulma is the most common form to be found 

 in the Eocene of Pamunkey river and shows great variation 

 in size and form. 



Some specimens are plano-convex while others are distindlly 

 bi-convex. Transverse secftions show the same nummuline lamin- 

 ation as shown in figure 21 (woodcut; of the Challenger Report. 

 The Jurassic Epistomina of Dr. Uhlig (Jahrb. k. k. Geol. 

 Reichsanstalt, vol. xxiii, p. 770, pi. vii, fig. 10 and pi. 

 VIII. figs, I — 3,) are very similar to our specimens but the 

 aperture does not appear to be the same. According to Professor 

 Brady this species is almost identical with Pidvinulina partschi- 

 ana d'Orbigny for he states that "The Rotalia elegans of the 

 '■Tableau Method ique, founded upon figures in Soldani's ' Testa - 

 ceographia' passes by insensible gradations into the Rotalina 

 partschiana of the Vienna Basin memoir. The particular variety 

 represented by the former figure attains larger dimensions, the 

 test is less convex and therefore relatively thinner, and the septa 

 are marked by broad, clear lines, neither elevated nor depressed, 

 whilst in the latter the sutures, especially on the inferior face, 

 are generally more or less limbate externally. ' ' 



This author further states that Pidvinulina elegans occurs in 

 comparatively shallow water while Pulvinulina partschiana is a 

 deep water form. 



Horizon and locality. — Eocene; Pamunky river, Va. 



Geological distributio?i . — Jurassic to Recent. 



Pnlvinulina schreibersii. 



Syn. Rotalina schreibersii d'Orbigny, 1846, Foram. Foss. Vien., p. 154, 

 pi. VII, figs. 4 — 6. 

 Pulvinidina schreibersii Bagg, Johns Hopkins Univ. Circulars, 

 vol. XV, p. 5, 1895. 



Test orbicular, superior side more convex than inferior; con- 

 sisting of about seven chambers in final convolution, (some speci- 



