PLATE XXIII. 



rsntdo-pcrna rii<:;osa, n. sp. 

 Fig. I. Exterior of right valve, young. 

 Fig. 2. Interior of right valve, young. 

 Fig. 3. Exterior view of right valve, very young. 

 Fig. 4. Interior view of right valve, adult. 

 Fig. 5. Exterior view of right valve, adult. 



Fseiido-pcrna torta, 11. sp. 

 Fig. 6. Exterior view of right valve. 

 Fig. 7. Interior view of right valve. 



Pscudo-penia attcniiata, 11. sp. 

 Fig. 8. Interior of right valve. 

 Fig. g. Exterior of right valve. 



Pscudo-pcrna orlnciilaris. n. sp. 

 Fig. 10. Exterior of left valve. 

 Fig. II. Interior of left valve. 



