INDEX OF PLATES. r6l 



8. Agomphus pectoralis. Both hyoplastra of type, lower surface. X 0.5. 



9. Agomphus pectoralis. Same bones seen from in front. X 0.3. 



10. Zygoramma striatula. Inner surface of a bridge peripheral of type, showing end of rib. 



X 0.4. In A. M. N. H. 



11. Baptemys wyomingensis. Skull seen from above. X 0.75. No. 484 Yale Univ. coll. 



12. Baptemys wyomingensis. Same skull seen from below. X 0.75. 



13. Baptemys wyomingensis. Same skull seen from side. X 0.75. 



PLATE 38. 



1. Zygoramma striatula. Both hypoplastra of type. X 0.5. In A. M. N. H. 



2. Zygoramma striatula. Three peripherals and part of costal of type. X 0.5. 



3. Zygoramma striatula. Same bones, inner surface. X 0.5. 



4. Hoplochelys crassa. Sixth right peripheral of type, outer surface. X i. No. 6091 



A. M. N. H. 



5. Hoplochelys crassa. Same bone, inner surface. X i. 



6. Hoplochelys crassa. Fourth or fifth peripheral of type, outer surface. X i. 



7. Hoplochelys crassa. Same bone, inner surface. X i. 



8. Hoplochelys crassa. Proximal ends of two costals of type, showing lateral carina. 



9. Hoplochelys crassa. Pygal of type. X i. 



10. Baptemys wyomingensis. Skull seen from above. X i. No. 5967 A. M. N. H. 



PLATE 39. 



1. Alamosemys substricta. Carapace of type. X 0.25. No. 1204 A. M. N. H. 



2. Alamosemys substricta. Plastron of type. X 0.25. 



PLATE 40. 



1. Baptemys wyomingensis. Carapace. X ]/$. No. 1494 A. M. N. H. 



2. Naomichelys speciosa. Entoplastron forming type, outer surface. X 0.75. No. 6136 



A. M. N. H. 



3. Naomichelys speciosa. Same bone, inner surface. X 0.75. 



PLATE 41. 



1. Baptemys wyomingensis. Carapace. X 0.28. No. 5967 A. M. N. H. 



2. Baptemys wyomingensis. Plastron of same specimen. X 0.28. 



PLATE 42. 



1. Baptemys fluviatilis. Carapace of type. X 0.24. Geol. Dept. A. M. N. H. 



2. Baptemys fluviatilis. Plastron of type. X 0.24. 



PLATE 43. 



1. Anosteira ornata. Carapace. X i. No. 6132 A. M. N. H. 



2. Anosteira ornata. Plastron. X i. 



PLATE 44. 



1. Gyremys spectabilis. Carapace of type. X 0.25. No. 1171 A. M. N. H. 



2. Gyremys spectabilis. Plastron of type. X 0.25. 



PLATE 45. 



1. Clemmys morrisia. Anterior lobe of plastron of type, upper surface. X 0.8. No. 6029 



A. M. N. H. 



2. Clemmys morrisia. Part of right side of hinder lobe of plastron, upper surface. X 0.8. 



No. 6029 A. M. N. H. 



3. Clemmys morrisice. Upper surface of left xiphiplastron. X 0.8. No. 6025 A. M. N. H. 



4. Clemmys hesperia. Left hyoplastron. Type. X i. No. 2219 Univ. Cal. coll. 



5. Clemmys hesperia. Right epiplastron. X i. No. 2179 Univ. Cal. coll. 



6. Clemmys hesperia. First right peripheral. X i. No. 2179 Univ. Cal. coll. 



7. Clemmys hesperia. Ninth left peripheral. X i. No. 532 Univ. Cal. coll. 



