196 STUDIES IN GEOLOGY, No. 3 



PLATE X. 



Figs. 1,2. Tellina zapotalensis Spieker. 



3. Tellina (Eurytellina) aequicincta Spieker. 



4. Tellina (Angulus) pressa Ball, side view x5. 



5. Tellina (Angulus) singewaldi Spieker. 



6. Pitaria (Lamelliconcha) planivieta (Guppy). 



7. Solecurtus (Pharella) planifolliculus Spieker. 

 8,9. Mulina zorritensis (Nelson). 



10. Labiosa (Raeta) gardnerae Spieker. 



11. Labiosa (Raeta) ventricosa Spieker. 



12. Corbula (Aloidis) prenuncia Spieker, x3. 



13. 14. Corbula (Aloidis) bradleyi Nelson. 



15. Corbula (Cuneocorbula) fabiformis Spieker, x3 



16. Corbula (Cuneocorbula) propinqua Spieker. 



17. Corbula (Cuneocorbula) bravoana Spieker. 



18. 19. Corbula (Cuneocorbula) acutirostra Spieker. 



