PLATE XXIII a. 



Fig. 2-4. — Right side of temporal and occipital region witli atlas and axis of the specimen of Byrachyua 



fxijiiJKS, figured in pUite LIV; one-third nature. 

 Fig. 1. — CrocodiUis pohjodon Cops. Dist.il portion of dentary bouc, natural size. Page 154. 

 Fig. 2. — Mandible in profile one-third natural size; 2, the angular and articular regions; 'ia, tho 



dentary. 

 Figs. 5-9. — Crocodilim aubiilalus Cope; natural size. 4. Part of dentary bone. Page 152. 

 Fig. 5. — Fragment of premaxillary. 



Fig. r>. — Cervical vertebra (third); 7a, jiroOle ; 7b, anterior extremity. 

 Fig. 7. — Anterior articular extremity of a dorsal vertebra. 

 Fig. 8. — Fragment of tooth, probably anterior premaxillary ; 9 a, section. 

 Fig. 9. — Articular region of the same, .6 natural size. 

 Figs. 10-18. — Crocodilualictcrodoii. 11-13, type from near Black Butte; 14-18, from near Laclede ; 19-23, 



Upper Green River; 11, 12, .6 natural size; 12a and 14, twice natural size; remainder, natural size. 



Page 164. 

 Fig. 10. — Cranium, from above; fig. 11, same skull, the muzzle from below. 

 Fig. 11(1. — Premaxillary teeth. 

 Fig. 12. — Basisphenoid bone, natural size. 

 Fig. 14. — Portion of right maxillary. 

 Fig. 15. — Posterior lumbar vertebra. 

 Fig. 16. — First caudal vertebra; a, from above. 

 Fig. 17. — Femur of same. 



Figs. 18-22. — Dermal scuta of another specimen. 

 Fig. 23. — Tooth of Crocodilui sulci/eriia Cope. Page 157. 



