EXPLANATION OF PLATE XXXVI. 



Figs. 1-3. Tylosaurus proriger: 



Figs. 1, 2. A caudal vertebra, one-half the natural size. From the Cretaceous of Kansas. 



Smithsonian Institution. 

 Fig. 1. Left lateral view. Fig. 2. Posterior view. 

 Fig. 3. A tooth which accompanied the former specimen, lateral view, natural size. 



Figs. 4-14. Lestosaurus coryphaeus. All the figures one-half the natural size. From the Cretaceous 



of Kansas. Museum of the Smithsonian Institution. 

 Fig. 4. Inferior view of a dorsal vertebra. Within the position of the right zygapophysis a 



rudimental zygosphene is observed. 

 Fig. 5. Inferior view of a second specimen. 

 Fig. 6. Inferior view of the body of a cervical vertebra. 

 Fig. 7." Eight lateral view of another cervical vertebra. 

 Fig. 8. Left lateral view of an anterior caudal vertebra. 

 Fig. 9. Same view of a more posterior specimen. 

 Fig. 10. Posterior view of the same. 



Fig. 11. Left lateral view of the bodies of two posterior vertebra}. 

 Fig. 12. Posterior view of the second of the latter. 

 Fig. 13. Limb-bone, probably an ulna or a fibula. 

 Fig. 14. Probably a radius or a tibia. 



Fig. 15. Mosasaurus: 



A caudal vertebra, from L'Eau qui Court County, Nebraska. Museum of Swarthmore Col- 

 lege. Presented by George S. Truman. Inferior view one-half the natural size. 



Fig. 16. Tylosaurus dyspelor. Inferior view of the same caudal centrum as that of Fig. 4, of the 



preceding plate. Half the natural size. 

 Figs. 17-21. Limb-bones of a turtle, from the Cretaceous of Smoky Hill River, Kansas. 



Smithsonian Institution. Three-fourths the natural size. 

 Fig. 17. Upper extremity of the right humerus, anterior view. 

 Fig. 18. The right femur, anterior view. 

 Fig. 19. Portion of a left scapula, inverted in position. The broken process to the left is 



the precoracoid. Posterior view. 

 Fig. 20. Portion of the coracoid. The articular surface at the upper end is for the scapula. 

 Fig. 21. Portion of an undetermined limb-bone. 



