244 SYSTEMATIC PALEONTOLOGY 



Genus POLYMORPHINA d'Orbigny. 

 POLY^MOEPHINA AUSTRIACA (cVOrbigllv). 



Plate LXIII, Fig. 7. 



Giittulina austriaca d'Orbigny, 1846, Foram. Fossiles Vienne, p. 223, pL xii, tigs. 



23-25. 

 Polymorphina austriaca Sch wager, 1877, Boll. R. Com. geol. Ital., vol. viii, p. 25, 



pi. xxxi. 

 Polymorphina austriaca Bagg, 1896, Bull. 141, U. S. Geol. Survey, p. 91. 

 Polymorphina austriaca Bagg, 1898, Bull. Amer. Pal., No. 10, p. 28. 



Description. — Test oviform, smooth, moderately compressed, acum- 

 inate anteriorly; consisting of four chambers which are oblong, oblique, 

 and somewhat convex; separated by fairly deep sutures; aperture mam- 

 millate. 



d'Orbigny considers that Guttulina nitida is closely related to this 

 species but states that it differs from it in its more elevated chambers. 

 Our specimens are slightly more acuminate posteriorly than in d'Or- 

 bigny's figure. Professor Brady lists this form among the synonyms of 

 Polymorphina prohlema but d'Orbigny has shown that it difEers from the 

 latter by its more convex chambers and more gibbous form as a whole. 

 Since the specific variations among the Polymorpliinae are necessarily 

 limited there is a possible danger of including too many variations under 

 one species and it is preferable, therefore, to keep the species distinct 

 as d'Orbigny has done. 



d'Orbigny's specimens were from the Miocene of Nussdorf, Baden. 

 It is not a common fossil form but Terquem has identified it among 

 the Eocene Foraminifera of the Paris Basin. 



Occurrence. — Nanjemoy Formation. Woodstock. 



Collection. — Johns Hopkins University. 



Polymorphina communis (d'Orbigny). 

 Plate LXIII, Figs. 8, 9. 



(intlidina commmds d'Orbigny, 1826, Ann. Sci. Nat., vol. vii, p. 266, No. 15, pi. xii, 



tigs. 1-4. Modele, No. 62. 

 Polymorphi?ia communis Brady, 1884, Chal. Rept., vol. ix, p. 568, pi. Ixxii, tig. 19. 

 Polymorphina communis Bagg, 1896, Bull. 141, U. S. Geol. Survey, p. 92. 

 Polymorphina communis Bagg, 1898, Bull. Amer. Pal., No. 10, p. 29. 



Description. — Test irregular, ovoidal, or egg-shaped; consisting of four 



or five distinct cli ambers; anterior end extremely acute, posterior obtuse; 



