215 vSt. Maurice and Claibornk Prlecypoda 21 



Fioure 



PI.ATK 14 



Page 



1. Pedcn 7i.'ant.:ibbca!ius Dall, X 2 .^ 21 



Right valve, common form, showing tripartite subdivision of 

 ribbing near the basal margin ; lack of strong ribbing over 

 nmch of the surface of the valve. Wautubbee, Miss. 



2. The same, X 2 ; showing well defined but unornamented rib- 

 bing in umbonal region. Hickory, Miss. 



3. The same, X 2, left valve. Notice the simple ribbing till the peri- 

 pheral region is reached ; also the well marked ornamenta- 

 tion of ribs throughout. Hickory, Miss. 



4. The same, right valve ; X 1.5 ; interior. 



5. Variety oi icaufubbianus, X 1.6 23 



Large, very thin, with dual subdivision of costte. From the 

 basal beds, Claiborne Bluff. 



6, 7. Variety wilkoxi Dall, X 3 23 



From specimens furnished by the U. vS. Nat. Mus. , from "Fo- 

 cene, Clark Co., Ala." 



8. Variety caz«<fz Harris, X 2.2 24 



Right valve, from Wautubbee, Miss. 



9. Peden pulchricosta lAx. and Aid., X 2 24 



Showing characteristics mentioned by the describers. Wautub- 

 bee, Miss. 



10. The same, X 2.5, left valve, showing characteristictics men- 

 tioned by Dall (Tr. Wag., p. 730). Wautubbee, Miss. 



n. Pedeti {darkeanusf var. ) burlesotiensis, n. var., X 2 26 



From a specimen furnished by the U. S. Nat. Mus. , from 

 "Black Bluff Shoals", Brazos River, Texas. 



12. The same, X 1%. From "Burleson Bluff", Brazos River, Te.x. 



13. The same, X lYz. From .^"Collier's Ferry", Brazos River, 

 Texas State Museum specimen. 



