50 SPECIES OF EXOGYRA FROM THE EASTERN GULF REGION AND THE CAEOLINAS. 



collections from beds near San Carlos, Presidio County, regarded as synchronous with a part of 

 the Taylor marl. (U. S. Geol. Survey coll. 1467 and Stanton's field No. 297.) The last-named 

 collection was made by Yaughan and Stanton. (See p. 45.) 



Localities. — This variety has been obtained in the eastern Gulf region from 24 localities, 

 detailed descriptions of which accompany the tables, pages 24—25 of this report. Some of the 

 more typical localities are the f ollowing : 



U. S. Geol. Survey colls. 5395, 6404. — Bluff on Chattahoochee River at Florence, Stewart County, Ga. Ripley 

 formation, Exogyra ponderosa zone. 



U. S. Geol. Survey colls. 5390, 6406. — Banks Landing, Chattahoochee River, 26J miles below Columbus, in Stewart 

 County, Ga. Tombigbee sand member of the Eutaw formation. 



U. S. Geol. Survey coll. 6441. — Public road, ljmiles east of Old Hamburg, Perry County, Ala. Top of Tombigbee 

 sand member of Eutaw formation. 



U. S. Geol. Survey colls. 64286, 6932. — Erie Bluff, 'Warrior River, Greene County, Ala. Top of Tombigbee sand 

 member of Eutaw formation. 



IT. S. Geol. Survey coll. 6920. — Gullies near Plymouth Bluff, Tonibigbee.River, 4 or 5 miles northwest of Colum- 

 bus, Miss. Base of Selma chalk. 



U. S. Geol. Survey colls. 68S6, 6888. — One mile west of Cotton Gin Port, Monroe County, Miss. Base of Selma 

 chalk. 



U. S. Geol. Survey coll. 6892. — Gullies on Erskine Miller's place, near Black Oak Grove church, 7 miles northeast 

 of Okolona, Monroe County, Miss. Selma chalk, Exogyra ponderosa zone. 



U. S. Geol. Survey coll. 6455. — Cut of Mobile & Ohio Railroad south of Booneville, Prentiss County, Miss. Base 

 of Selma chalk of northern Mississippi (within 50 to 100 feet of top of Exogyra ponderosa zone). 



U. S. Geol. Survey coll. 6928. — Exposures in Selmer-Adamsville road, one-quarter mile west of Adamsville, 

 McNairy County, Term. Impure phase of Selma chalk, near to top of Exogyra ponderosa zone. 



The variety has been collected from the following localities m the Carolinas : 



U. S. Geol. Survey coll. 5366. — Iron Mine Landing, Black River, 51 miles above Wilmington, N. C. Near top of 

 Black Creek formation. 



TJ. S. Geol. Survey coll. 5372. — Hodge's old mill, 3J miles southeast of Mullins, Marion County, S. C. Top of Black 

 Creek formation. 



In addition to these localities specimens which should perhaps be referred to this variety 

 have been found on Cape Fear River at Donohue Creek Landing, 50J miles above Wilmington, 

 and at Kelly's Cove Landing, 46 miles above Wilmington, Bladen County, N. C, the beds from 

 which they were taken being in each case stratigraphically near the base of the Peedee sand. 

 This is a slightly higher range than the known range of the variety in the eastern Gulf region. 



Exogyra costata Say. 



Plate XVI, figures 3, 4; Plate XVII. figures 1, 2; Plate XVIII: Plate XIX, figures 1, 2, 3, 4; Plate XX. figure 1. 



1820. Exogyra costata Say, Am. Jour. Sci., let ser., vol. 2, p. 43. 



1828. Exogyra costata Morton. Jour. Acad. Nat. Sci. Philadelphia, 1st ser., vol. 6, p. 85, PL VI, figs. 1-4. 



1830. Exogyra costata Morton, Am. Jour. Sci., 1st ser.. vol. 17, p. 2S4. 



1834. Exogyra costata Morton, Synopsis of the organic remains of the Cretaceous group of the United States, pp. 55- 



56, PI. VI, figs. 1-1. 

 l)S-i0. Exogyra costata Troost. Fifth Geol. Rept. Tennessee, p. 46. 

 1849. Exogyra costata Roemer [?], Texas, Bonn. 1S49, p. 396. 

 1852. Exogyra costata Roemer ['?], Kreidebildungen von Texas, Bonn, p. 72. 



1857. Exogyra costata Conrad, Rept. U. S. and Mex. Boundary Survey, vol. 1, pt. 2, pp. 154-155, PI. IX, fig. 2a-b, 



PI. X, fig. 1. 



1858. Exogyra intcrrupta Conrad, Jour. Acad. Nat. Sci. Philadelphia, 2d ser., vol. 3, p. 330, PI. XXXIV, fig. 15. 

 1858. Exogyra costata Emmons, Rept. North Carolina Geol. Survey, p. 278, fig. A. 



1S60. Exogyra costata Owen, Second Rept. Geol. Recon. Arkansas, PI. VII, fig. 4. 



1861. Exogyra costata Gabb, Synopsis of the Mollusca of the Cretaceous formation, p. 122. 



1S64. Exogyra costata Meek. Check list of the invertebrate fossils of North America, Cretaceous and Jurassic, Smith 



soman Misc. Coll., vol. 7 i X . 177 , p. 6. 

 81 8. Exogyra costata Conrad, Cook's Geol. New Jersey, p. 374. fig. 1, p. 724. 

 L869. Ostrea torosa Coquand (in part). Monographie du genre Ostrea. terrain cretace. Paris, p. 38, PI. XIV, figs. 1-1, 



PI. XV, figs. 1. 2. 

 1876. Exogyra costata Gabb, Proc. Acad. Nat. Sci. Philadelphia, 1876, p. 323. 



