i84 



Studies in Geology^ No. 3 



Plate IV. 



Figs. 1,2,3. Turritella prenuncia Spieker. 



1. X3. 



2. x5. 



3. X2. 

 Turritella prenuncia var. inconspicua Grzybowski, x2. 

 Turritella robusta Grzybowski. 

 Turritella robusta var. abrupta Spieker. 

 Turritella cbarana Spieker. 

 Polynices subangulata Nelson. 



9. Polynices porcana Spieker. 



10. Sinum carolanum Spieker, X5. 



11. Turbo belli Spieker, X2. 



12. Turbo belli var. aequifilicatus Spieker. 



13. Cancellaria (Aphera) peruana Nelson, x2. 



