

THE EOCENE PERIOD 



795 



abundant, the corals had taken on modern forms, and decapods 

 were rising in importance. 



The American Eocene faunas 1 were rather pronouncedly pro- 

 vincial, though some species have a rather wide range. So pro- 

 nounced is the provincial character of the faunas, that much 

 | difficulty is experienced in making correlations between formations 



^\ 



d 



****** /^^L s^\ 



> 5 # 



Fig. 534. EOCENE FORMINIFERA. a, Nodosaria bacillum Def ranee; b, N. 

 communis (d'Orbigny); c, Anomalina ammonoides (Reuss); d, Cris- 

 tellaria gihba d'Orbigny; e, C. radiata (Bornemann); /, g, and h, Globi- 

 gerina bulloides d'Orbigny; i, Vaginalina legumen (Linne) ; /, Discorbina 

 turbo (d'Orbigny); k, Truncatulina lobatula (Walker and Jacob) ; Z, Tex- 

 tularia subangulata (d'Orbigny). Magnified 8 to 40 times. (Maryland 

 Geol. Surv.) 



along different parts of the Atlantic and Gulf coasts, and greater 

 difficulties arise in regions more widely separated. The variations 

 are, however, variations of detail, not of broad features. 



1 W. H. Ball, Trans. Wagner Free Inst. Sci., Vol. Ill, 1890-1900; Bull. 

 141, U. S. Geol. Surv., 1896; W. B. Clark, Md. Geol. Surv., Eocene volume, 

 1901; R. M. Bagg, Bull. 141, U. S. Geol. Surv., 1896; A. Heilprin, Proc. Acad. 

 Nat. Sci. Phil., Vol. XXXI, 1879; Vol. XXXII, 1880; and Vol. XXXIII, 1881; 

 I Jour. Acad. Nat. Sci. Phil., Vol. IX, 1884; T. W. Vaughan, Bull. 141, U. S. Geol. 

 Surv., 1896; Mon. XXXIX, U. S. Geol. Surv., 1900; T. W. Stanton, 17th Ann. 

 Kept., U. S. Geol. Surv., Pt. I, 1895-6; G. D. Harris, Am. Pal. Bull., Vols. I 

 and II. 



