138 Bulletin 4 253 



Explanation of Plate 6. 



( 16 ) 



Page. 



Fig. I. Crassatella sepulcollis n. sp 64, 178. 



Exterior view, 

 a. Interior view. 



2. Protocardia nicolletti var 65, I79» 



3. Cardium sp., 18 mi. S. E. of Eagle Pass, Texas. 



4. Chama gainesensis n. sp 66, 180. 



Cast, 

 a. Gutta-percha mould, showing exterior marking. 



5. Isocardia mediavia n. sp " " 



6. Meretrix ripleyana Gabb 67, iSl. 



•7. Meretrix ripleyayiaf Gabb....... " " 



8, Tellina sp 68, 182. 



9. Corbula subcompressa Gabb 0. " " 



10. Lucma claytonia n. sp 69, 183. 



Exterior view, gutta-percha mould, 

 a. Interior view, gutta-percha mould. 



11. Lucina fortidentalis n. s^ " " 



Exterior, cast, 

 a. Interior, cast. 



12. GastrochcBna gainesensis n. sp. , X2 70, 184. 



Cast of left valve, 

 a. Impression of exterior in its original matrix. 



13. GastrochcBTia cimitariopsis n. sp. , X2 " " 



14. Gastrochcena sp. , young, (from Ft. Gaines), x 2. 



15. Martesia dalliana n. sp., xi^ 71, 185. 



16. Verticordia sp " " 



17. Pholadomya mauryi n. sp " " 



Exterior, right valve. 

 a. Anterior view. 



