PLATE XIII. 



ExOGYRA UPATOIENSIS sp. nOV. (p. 46). 



Figure 1. — Specimen with both valves attached, from basal beds of the Eutaw formation. Broken Arrow Bend, Chat- 

 tahoochee River, 10i miles below Columbus, Ga. (U. S. Geol. Survey coll. 5384). Shows ornamentation 

 of left or lower valve and scar of attachment to a univalve shell. 



2. — Same specimen as preceding, showing right or upper valve. 



3. — Left valve of a nearly complete specimen from basal beds of Eutaw formation, bluff of Upatoi Creek, 

 below bridge of Columbus-Cusseta road, 7 miles southeast of Columbus, in Chattahoochee County, Ga. 

 (TJ. S. Geol. Survey coll. 5317). Shows character of ornamentation toward apical portion; apex some- 

 what distorted by scar of attachment to a univalve shell. 



4. — Large left valve from same locality as specimen shown in figure 1 (U. S. Geol. Survey coll. 5384). Shows 

 a weaker development of costae than on preceding specimens, and scar of attachment to a bivalve shell. 



Exogyra ponderosa Roemer (p. 46). 



Figure o.— Specimen with both valves attached, from the Tombigbee sand member of the Eutaw formation {Exogyra 

 ponderosa zone. Mortoniceras subzone); bluff at Blufftown, Chattahoochee River, 31^ miles below 

 Columbus, Ga. 1". S. ( ieol. Survey coll. (HOod). Shows development of small costae on apical portion 

 of shell. 



6. — Same specimen as preceding, showing absence of costae on all but apical portion. 



7. — Another view of the same specimen. A small scar of attachment appears on the tip of the beak. 



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