BIBLIOGRAPHIC LIST OF GENERA AND SPECIES. 881 



Opisthoptera easel (Meek and Worthen). 



Ambonychia (Megaptera) casei Meek and Worthen, Proe. Chicago Acad. Sci., 1, 



1866, p. 23; Geol. Surv. Illinois, 3, 1868, p. 337. 

 Opisthoptera casei Ulrich, Geol. Surv. Ohio, 7, 1893, p. 643, pi. 49, figs. 1-5. 



Cumings, 32d Ann. Rep. Dep. Geol. Nat. Res. Indiana, 1908, p. 1011, pi. 47, 



figs. 1, la. 

 Richmond: Richmond, etc., Indiana (Whitewater); Waynesville and Clarksville, 



Ohio; near Lebanon, Kentucky. 

 Pleziotypes.Cat. Nos. 46264, 46265, .U.S.N.M. 



Opisthoptera conordensis Foerste. 



Opisthoptera concordensis Foerste, Bull. Sci. Lab. Denison Univ., 16, 1910, p. 



70, pi. 1, fig. 9. 

 Richmond (Arnheim): East of Concord, Kentucky. 



Opisthoptera extenuata Ulrich. 



Opisthoptera extenuata Ulrich, Geol. Surv. Ohio, 7, 1893, p. 645, fig. 2a-d. 

 Richmond (Waynesville): Warren County, Ohio. 

 Holotype.C&t. No. 46266, U.S.N.M. 



Opisthoptera flssicosta (Meek). 



Ambonychia (Megaptera) casei? Meek, Ohio Pal., 1, 1873, p. 133. (fissicosta 



suggested.) 

 Opisthoptera fissicosta Ulrich, Geol. Surv. Ohio, 7, 1893, p. 644, pi. 49, figs. 9 and 



11; p. 645, fig. 



Richmond (Waynesville): Waynesville, Clarksville, etc., Ohio. 

 Plesiotype.Csit. No. 46267, U.S.N.M. (Ulrich). 



Opisthoptera laticostata Ulrich. 



Opisthoptera laticostata Ulrich, Geol. Surv. Ohio, 7, 1893, p. 646, pi. 47, fig. 6. 

 Richmond (Waynesville) : Warren County, Ohio. 

 Holotype.C&t. No. 46268, U.S.N.M. 



Opisthoptera notabilis Ulrich. 



Opisthoptera notabilis Ulrich, Geol. Surv. Ohio, 7, 1893, p. 648, pi. 49, fig. 16. 

 Maysville (Fairmount): Cincinnati, Ohio. 

 HolotypeCa,t. No. 46269, U.S.N.M. 



Opisthoptera obliqua Ulrich. 



Opislhoptera obliqua Ulrich, Geol. Surv. Ohio, 7, 1893, pi. 49, figs. 6-8. Cumings, 

 F ' Ann. Rep. Dep. Geol. Nat. Res. Indiana, 1908, p. 1012, pi. 47, figs. 2, 2b. 

 Richmond (Whitewater): Richmond, Indiana. 

 Holotype.V&t. No. 46270, U.S.N.M. 



ORBICULA? DEFORMATA Hall. See Archinacella deformata. 





Orbicula? excentrica Emmons. 



Orbicula excentrica Emmons, Amer. Geol., 1, pt. 2, 1855, p. 112, pi. 1, fig. 4. 

 Barrande, Bull. Soc. Geol. France, 2d ser., 18, 1861, p. 300, pi. 5, fig. 17. 

 Lesley, Geol. Surv. Pennsylvania, Rep. P 4, 1889, p. 502, fig. Schuchert, 

 Bull. U. S. Geol. Surv., 87, 1897, p. 277. 

 Crania excentrica Miller, N. A. Geol. Pal., 1889, p. 341. 

 Lower Martinsburg: Augusta County, Virginia. 

 Observation. Probably an Archinacella. 



ORBICULA? FILOSA Hall. See Schizocrania filosa. 

 ORBICULA LAMELLOSA Hall. See Orbiculoidea lamellosa. 



