ILLUSTRATIONS XHI 



A Neiakly Complete Sheix of the Extinct TirB.Ti.E, Tbachemys 



SotTLPTA 



By Charles W, Gilmore 



Page 



1. Carapace of Trachemys sculpta Hay. Cat. No. 11839, U.S.N.M. 



Nearly one-third natural size 3 



2. Plastron of Trachemys sculpta Hay. Cat. No. 11839, U.S.N.M. 



Nearly one-third natural size 4 



On DiNosAtmiAN RefttleS' feom the Two Medicine Formation of 



Montana 



By Charles W. Gilmore 



1. Skull of Palaeoscincus rugosidens. Type. No. 11868, U.S.N.M. Poste- 



rior view. One-third natural size. Bs. Pt. Proc, basipterygoid 

 process, of the basisphenoid ; Ect., ectopterygoid ; Ew. oc, exoccipital ; 

 L. T. F., lateral temporal fenestra ; Oc, occipital condyle ; P. oc, 

 paraoceipital process ; Pt., pterygoids ; Qu., quadrate ; 8. oc, supra- 

 occipital ' 4 



2. Skull of Palaeosomcus rugosidens. Type. No. 1186S, U.S.N.M. 



Interior view. One-third natural size. Bs. Pt. Proc, basipterygoid 

 processes ; Ect., ectopterygoid ; Ex. oc, exoccipital ; L. T. F.. lateral 

 temporal fenestra ; Maoe., maxillary ; Nar. Vac, narial vacuity ; 0, 

 orbit ; Oc, occipital condyle ; Pmx., premaxillary ; Prv., prevomer ; 

 Pt., pterygoids ; Qu., quadrate ; Quj., quadratojugal ; 8q., squamosal ; 

 IX, XI, XII, exits for cranial nerves 6 



3. Right ramus of Palaeoscincus rugosidens. Type. No. 11868, U.S.N.M. 



A, Inner view ; B, superior view. Both one-third natural size. 



Art., Articular ; C, coronoid ; 8., symphysical border 9 



4. Maxillary tooth of Palaeoscincus rugosidens. Type. No. 11868, U.S. 



N.M. Internal view. Two and one-half times natural size 10 



5. Crown of germ maxillary tooth of Palaeoscincus rugosidens. Type. 



No. 11868, U.S.N.M. Internal view. Two and one-half times nat- 

 ural size 10 



6. Atlas and axis of Palaeoscincus rugosidens. Type. No. 11868, U.S. 



N.M. A, Lateral view; B, posterior view of axis, about one-third 

 natural size. At., Atlas ; Ax., axis ; 1st C. R., first cervical rib 12 



7. Third cervical vertebra of Palaeoscincus rugosidens. Type. No. 



11868, U.S.N.M. Lateral view. One-third natural size 13 



8. Fifth ? cervical vertebra of Palaeoscincus rugosidens. Type. No. 



11868, U.S.N.M. Lateral view. One-third natural size 13 



9. Seventh ? cervical vertebra of Palaeoscincus rugosidens. Type. No. 



11868, U.S.N.M. A, Lateral view; B, anterior view. Both figures 

 one-third natural size 14 



10. Anterior dorsal vertebra of Palaeoscincus rugosidens. Type. No. 



11868, U.S.N.M. A, Lateral view ; B, anterior view. Both figures 

 one-third natural size 15 



11. Posterior dorsal vertebra, with coossified rib of Palaeoscincus rugo- 



sidens. Type. No. 11868, U.S.N.M. Posterior view. About one-fifth 

 natural size 16 



12. Third caudal vertebra of Palaeoscincus rugosidens. Type. No. 11868, 



U.S.N.M. A, Lateral view ; B, anterior view. Both figures about 

 one-third natural size 18 



