1921] 



NATURAL SCIENCES OF PHILADELPHIA. 435 



Fig. 8. — Metis postrema Pils. & Johns. Type. 



Fig. 9. — Semele delimata Pils. & Johns. Type. 



Fig. 10. — Semele fir ma Pils. & Johns. Type. 



Fig. 11. — Labiosa gahbi Pils. & Johns. Type. 



Figs. 12, 13. — Corbula dominicensis Gahh. Cotypes. 



Fig. 14. — Corbida knoxiana fossilis Pils. & Johns. Type. 



Plate XLVII. — Fig. 1, 2. — Chione santodomingensis Pils. & Johns. Type. 

 Figs. 3, 4, 5. — Chione guppyana Gabb. Type. 

 Figs. 6, 7. — Chione primigenia Pils. & Johns. Tj^pe. 

 Fig. 8. — Cyclina cyclica domingensis Pils. & Johns. T3^3e. 

 Fig. 9. — Dosinia aziiana Pils. & Johns. Type. 

 Fig. 10. — Pilar acuticostatus (Gabb). Type. 

 Fig. 11. — Pilar tryonianus (Gabb). Type. 

 Figs. 12, 13. — Chione socia Pils. & Johns. TjTie. 



Figs. S, 9 natural size, the others enlarged. 



