Plate 5 



(re-illustration of Vanderpool's types) 

 Figures 



la-c. Cypridea Wyoming ensis Jones, DeQueen Limestone at Gypsum Bluff, 

 Pike County, Arkansas, x 52. 



la. Exterior of paratype right valve, U.S.N.M. 132529 



lb. Interior of paratype right valve, U.S.N.M. 132530 



lc. Interior of paratype left valve, U.S.N.M. 132531 

 2a-d. Cypridea diminuta Vanderpool, DeQueen Limestone at Gypsum Bluff, 

 Pike County, Arkansas, x 52. 



2a. Left side of a paratype shell, U.S.N.M. 132524 



2b. Right side of a paratype shell, U.S.N.M. 132525 



2c. Ventral view of a paratype shell, U.S.N.M. 132526 



2d. Interior of a paratype left valve, U.S.N.M. 132527 

 3a-c. Cypridea dequeenensi* Swain and Brown, n. sp., DeQueen Limestone at 

 Gypsum Bluff, Pike County, Arkansas, x 52. 



3a. Right side of a paratype shell, U.S.N.M. 132520 



3b. Interior of a paratype right valve, U.S.N.M. 132521 



3c. Interior of a paratype left valve, U.S.N.M. 132522 

 4a-e. Eocytheropteron trinitiensis (Vanderpool), DeQueen Limestone at Gyp- 

 sum Bluff, Pike County, Arkansas, x 52. 



4a. Right side of a paratype shell, U.S.N.M. 132487 



4b. Interior of paratype right valve, U.S.N.M. 132488 



4c. Dorsal view of paratype shell, U.S.N.M. 132489 



4d. Left side of holotype shell, U.S.N.M. 132490 



4e. Interior view of a broken paratype left valve, U.S.N.M. 132491 

 5a-c. Eocytheropteron trinitiensis (Vanderpool), x 52. 



5a. Left side of broken paratype shell, U.S.N.M. 132492 



5b. Right side of a paratype shell, U.S.N.M. 132493 



5c. Interior view of a broken left valve paratype, U.S.N.M. 132494 

 6a-c. Cythereis praeornata Swain and Brown, n. name, DeQueen Limestone 

 at Gypsum Bluff, Pike County, Arkansas, x 52. 



6a. Exterior of holotype left valve, U.S.N.M. 132472 



6b. Interior of paratype left valve, U.S.N.M. 132473 



6c. Exterior of paratype right valve, U.S.N.M. 132474 



55 



