expla.:nation of plates. 



Fig. 1. Cautliarus? julesburgensis; lateral view. 



2. " " apertural view. 



3. Liicina clebunii; right-side view. 



4. " " dorsal view. 



5. Liicina profunda; right valve. 



6. " '• left valve. 



7. Pteria (Oxytoma) erecta; right valve. 



8. " " " left valve. 



9. Solemya bilix ; right valve. 



10. Callianassa iilrichi; leftinanus; exterior view. 

 IX. "■ " " interior view. 



12. Tubulostium dickhauti; lateral view. 



13. •' " peripheral view. 

 All of natural size. 



