1917.] NATURAL SCIENCES OF PHILADELPHIA. 41 



Explanation of Plates V and VI. 



Plate V. — Fig. 1. — Turris cartagenensis n. sp. 

 Fig. 2. — Marginella mediocris n. sp. 

 Fig. 3. — Stronibina cartagenensis n. sp. 

 Fig. 4. — Strotnbiiia lloydsmithi n. sp. 

 Fig. 5. — Pot amides aims n. sp. 

 Fig. 6. — Olim sayana immortua n. subsp. 

 Fig. 1 .—T urritella domingensis n. sp. 

 Fig. 7a. — Turritella domingensis. Part of the last whorl, enlarged. The 



figure is inverted. 

 Fig. 8. — Dentalium solidissimum n. sp. 

 Fig. 9. — Turritella domingensis, n. sp. Young shell. X 3. 

 Fig. 10. — Dentalium cartagenense n. sp. 

 Fig. 11. — Turritella lloydsmithi n. sp. 

 Fig. 12. — Turritella perattenuata 'prcecellens n. subsp. 

 Fig. 13. — Turritella cartagenensis n. sp. 

 Fig. 14. — Turritella megalobasis Dall. Part of a whorl much enlarged. 



The figure is inverted. 

 Fig. 15. — Turritella calostemma n. sp. 



Plate VI.— Figs. 1, la. — Ostrea vaughani insularis n. subsp. 



Figs. 2, 2a. — Ostrea sculpturala osculum n. subsp. Ventral and lateral views. 



Fig. 3. — Yoldia pisciforynis n. sp. 



Fig. 4. — Pilar casta n. sp. 



Fig. 5. — Glycymeris trilobicosta n. sp. 



Fig. 6. — Glycymeris lloydsmithi n. sp. 



Fig. 7. — Glycymeris tumefactus n. sp. 



Fig. 8. — Ostrea cahobasensis n. sp. Interior of deep valve. 



