132 



SHORTER CONTRIBUTIONS TO GENERAL, GEOLOGY, 1921. 



apical end bluntly pointed, apertural end 

 tapering; surface smooth; aperture radiate. 

 Length 1 millimeter or less. 



A few specimens have been collected in the 

 Mint Spring marl at the following stations: 



6452. Mint Spring Bayou, Vicksburg, Miss. 

 6647. Chickasawhay River 1| miles southwest of Boice, 

 Miss. 

 7671. "Brown's Cave," I/eaf River, Miss. 



Polymorphina gibba D'Orbigny. 



Polymorpkhm (Globulina) gihha D'Orliigny, Annales sci. 



nat., vol. 7, p. 226, No. 20, Modules, No. 63, 1826. 

 PolymoTphina gibba H. B. Brady, Parker, and Jones (part), 



Linnean Soc. London Trans., vol. 27, p. 216, pi. 39, 



figs. 2a-d, 1870. 

 11. B. Brady, Chalhnger Rept., Zoology, vol. 9, )>. 561, 



pi. 71, figs. 12a, b, 1884. 

 Ciishman, U. S. Nat. Mvis. Bull. 71, pt. 3, p. 85, pi. 



41, fig. 4, 1913; U. S. Geol. Surrey Bull. 676, p. 11. 



pi. 2, fig. 4; p. 52, pi. 11, fig. 5, 1918; U. S. Geol. 



Survey Vrof. Paper 129, p. 93, pi. 17, fig. 3, 1922. 



Test rotund, in front view nearly circular, in 

 end view broadly oval; chambers few, dis- 

 tinct; sutures distinct, but little if at all exca- 

 vated; wall smooth and translucent; aperture 

 slightly produced, radiate. Length 0.75 milli- 

 meter or less. 



Very rotund specimens which are here re- 

 ferred to this species were found in the Mint 

 Spring marl at the following stations: 



6447. tilass Bayou, \'ick8burg, Miss. 

 6451. Mint Spring Bayou, Vicksburg, Miss. 

 6647. Chickasawhay River \\ miles southwest of Boice, 

 Miss. 

 7671. "Brown's Cave," Leaf River, Miss. 



This species also occurs in the Byram marl, 

 and I have recorded it from the Pliocene 

 Caloosahatchee marl on Shell Creek, Fla., and 

 from the Miocene Calvert formation at Chesa- 

 peake Beach, Md. (Bagg), and Duplin marl at 

 Mayesville, S. C. 



Polymorphina amygdaloides (Reuss) Reuss? 



Olobulimi amygdaloides Reuss, Deutsch. geol. (iesell. 



Zeitschr.,'vol. 3, p. 82, pi. 6, fig. 47, 1851. 

 Polymorphitm amygdaloides (Reuss) Reuss, Akad. Wiss. 

 WieD Sitzungsber., vol. 18, p. 250, pi. 8, fig. 84, 

 1855. 

 H. B. Brady, ' 'kallenger Rept., Zoology, vol. 9, p. 560, 



pi. 71, fig. 13C.'), 1884. 

 Bagg, U. S. Nat. Mus. Proc, vol. 34, p. 148, 1908. 

 Cushman, U. S. Nat. Mus. Bull. 71, pt. 3, p. 85, pi. 

 41, fig. 5, 1913; U. S. Geol. Sur\ey Prof. Paper 129, 

 p. 95, pi. 18, figs. 2a, 2b, 1922. 



Test elongate-oval, much compressed, com- 

 posed of few chambers, which are elongate and 

 narrow; sutures rather indistinct, not de- 

 pressed; surface smooth; aperture somewhat 

 produced. Length 0.65 millimeter or less. 



Elongate specimens somewhat like those 

 figured in the paper on the Byram marl were 

 found in the Mint Spring marl at the following 

 stations : 



6447, 6448. Glass Bayou, Vicksburg, Miss. 

 6451, 6452. Mint Spring Bayou, \'icksburg. Miss. 

 7671. ' 'Brown's Cave," Leaf River, Miss. 



The specimens are very doubtfully identical 

 with the species of Reuss. 



Polymorphina equalis D'Orbigny. 

 Plate XXXI, figure 3. 



Polymorphina equalis D'Orbigny, Annales sri. nat.. vol. 



7, p. 265, No. 13, 1826. 

 Polymorphina aequalis D'Orbigny, Foraminif eres fossil es du 



liassin tertiaire de Vienne, p. 227, pi. 13, figs. 11. 12. 



1846. 

 Polymorphina gibba var. aequalis H. B. Brady, Parker, and 



.lones, Liuneau Soc. London Trans., vol. 27, p. 216, 



pi. 39, figs. 2c, d, 1870. 



Test compressed, broadly oval; periphery 

 rather evenly curved, rounded, composed of 

 few chambers; sutures distinct but very slightly 

 depressed; wall smooth; aperture radiate. 

 Length 0.7 to 0.8 millimeter. 



This species described by D'Orbigny occurs 

 sparsely in the Mint Spring marl at two sta- 

 tions : 



6448. Glass Bayou, Vicksburg, Miss. 



()451. Mint Spring Bayou, Vicksburg. Miss. 



Polymorphina advena Cushman, n. sp. 



Plate XXXI, figure 4. 



Test much compressed, broadly ovate; cham- 

 bers numerous, elongate, alternating, much the 

 broadest near the peripheral end; sutures 

 slightly depressed; surface ornamented with 

 numerous fine hmgitudinal costac, except the 

 last-formed one of two chambers, which are 

 smooth, at least at the apertural end; aperture 

 radiate. Length 1 millimeter. 



Type specimen from station 645 1, Mint 

 Spring Bayou, Vicksburg, Miss. 



This species is an unusual one for this genus, 

 appearing much more like a Bolivina, but it 

 has the characteristic aperture of Polymorphina. 

 It is perhaps closest related to Polymorphina 

 complanata D'Orbigny. 



