NO. :J1«9. MOLLUt<Kt^ OF CHOCTAW II. ITCHEE MARL-MAXtiFIELD. 607 



Type (Cat. No. 166913 U.S.N.M.)— This measures— length of 

 left valve, 16.5 mm.; height, 15 mm. 



This shell recalls Dvplodonta radiata Dall, from the Oligocene at 

 Oak Grove, Florida, but differs from it as follows: The surface is 

 smoother, the posterior side is more rounded, and the left posterior 

 cardinal is proportionally longer. 



The described specimen is somewhat eroded; the lower ventral 

 margin is wanting, which prevents a more detailed description. 



Type-locality. — Miocene of Florida, E. Gomillion's field, one-fourth 

 mile east of Redbay, Walton County, Florida. C. Wythe Cooke, 

 collector. 



EXPLANATION OF PLATE 113. 



Fig. 1. Arca(Scapharca) staminearubiwiiana, new subspecies; type; length, 36 mm. 

 natural size; p. 603. 



2. Ledachodaiuhatche'ensis, new species; type; length, 5.4 mm.; figure X5; p. 604. 



3. Interior view of figure 1; p. 603. 



4. Interior view of figure 2; p. 604. 



5. Phacoides (Pleurolucina) choctmvhalcheensis, new species; type; length, 10.3 



mm.; figui-e X3; p. 604. 



6. Exterior view of figiure 5; p. 604. 



7. Diplodonta ivaltonmsis, new species; type; length 16.5 mm.; figm-e XlJ; 



p. 606. 



8. Astarte (Ashtarotha) vaughani, new species; type; length, 9.5 mm.; figure 



X3; p. 605. 



9. Interior view of figure 8; p. 605. 



10. Area (Scapharca) staminea rubisiniana, new subspecies; figiired specimen; 



natural size. 



11. Chama ardnella Linnaeus; Jackson Bluff variety; natural size. 



12. Interior view of figure 11. 



Figs. 11 and 12 serve to illustrate the variety which is not described in the text. 



