329 Tertiary Foraminifera. 



35 



very slight septal depressions. The aperture is in the form of an 

 elongated slit reaching from the margin to near the umbilicus 

 upon the inferior surface. 



Diam., 0.39. 



I have onl}' one specimen of this minute shell. 



Hoidson and locality. — Miocene; Darlington, S. C. 



Geological distribution . — Miocene to Recent. 



Genus TRUNCATULINA d' Orbigny. 

 Truncatulina haidingerii 



Syii. Rotalina liaidingt'rii ^'Orhigwy, 1S46, Foram, Foss, Vien., p. 154, 

 pi. vii, figs. 7-9. 

 Rotalina ehrenbergii Bailey, Sniitl:sonian Contrib. to Knowl., 

 ^ vol. II, Art. 3, p. 10, figs. 11-13, 1851. 



Truncatulina haidingerii Brady^ Chal. Rep., vol. ix, p. 663, 

 pi. xcv, fig. 7, a-c. 1884. 

 Test circular, biconvex, trochoid, composed of three volutions. 

 Upon the inferior side the chambers are marked by nearly 

 straight somewhat depressed septa, while upon the superior side 

 the septa are more or less curved backward, often quite strongly 

 so. The aperture is in the form of a very small slit near the 

 periphery. 



This species is very similar to Truncatulina ungeriana but dif- 

 fers from it in being more vaulted and less depressed at the um- 

 bilicus. There is no distinct groove following the whorls upon 

 the superior side and the perforations are much smaller than in 

 its allied form. 



Our forms of this species from the well boring at Norfolk, Va., 

 found at a depth of 685 feet are of Tertiary age (lower?) and are 

 identical with Rotalia propinqua Reuss, which must be consid- 

 ered as a synonym of Truncatulina haidingerii d' Orbigny. 



Horizon and locality.— ^oxioVa, Va. Well boring, depth 685 

 feet. 



Geological distribution.— ^xoX.'A.Q.^ons to Recent. 

 •Truncatulina lobatula. 



Syn. Nautilus lobatulus^-slV&x &.l2.zoh, 1798, (fide Karmacher's Ed.) 

 Adams Essays Microsc, p. 642, pi. xiv, fig. 36. 

 Triincatuli7ia lobatula Brady, Chal. Rept., vol. ix, p. 660, pi. 

 xcii, fig. 10, pi. xciii, figs. 1,4, 5; pi. cxv, figs. 4, 5, 18S4. 

 Test plano-convex, moderately vaulted; last volution consist- 

 ing of seven, eight, or nine chambers with slightly depressed 



