PLEIOCENE FOSSILS. 



PLATE XVIi. 



ARCACID^.-NUCULTDiE. 



AKOAOIDJl. 



Pig. 1. PECTUNCULUS SUBOVATUS. Interior of right and exterior of left valve, natural size. Page 47. 



" 2. PECTUNCULUS LENTIFORMIS. Same views. Page 48. 



" 3. PECTUNCULUS PASSUS. Same views. Page 48. 



" 4. PECTUNCULUS QUINQUERUGATUS. Same views. Page 49. 



" 5. PECTUNCULUS LiEVIS. Same views. Page 50. 



" 6a. PECTUNCULUS ARATUS. Interior, natural size. Page 50. 



" 6b. Exterior, natural size. 



" 6. A large variety of the same. 



" 6c. PECTUNCULUS TRANSVERSUS. (A natural cast.) Page 51. 



NUOULIDJE. 



Fig. 7. NUCULA PROXIMA. Interior of right valve, natural size. Page 53. 



" 8. Exterior of left valve. 



" 9. Magnified view of hinge and teeth. 



" 10. NUCULA ACUTA. Exterior, natural size. Page 53. 



" 11. Interior, natural size. 



" 12. Magnified view of hinge and teeth. 



" 13. NUCULA LIMATULA. Exterior, natural size. Page 52. 



" 14. Interior, natural size. 



" 15. Magnified view of hinge and teeth. 



