638 Troxell — Vertebrate Fossils of Rock Creek, Texas. 



13. Merriam, J. C, 1912. Mem. Univ. Calif., vol. i, No. 2, pp. 215-272. 



14. Osborn, H. F., 1910. The Age of Mammals. New York. 



15. Osborn, H. F., 1912. Mem. Amer. Mus. Nat. Hist., vol. i, PL III, 

 pp. 55-100. 



16. Scott, W. B., 1913. A History of Land Mammals in the Western 

 Hemisphere. New York. 



LIST OF ILLUSTRATIONS. 

 Plate IX. Equus scotti, mounted specimen, Yale Collection. 



Fig. 1. Outline map of Rock Creek. 2 in. = 1$ miles. 



2. Restoration of Equus scotti, by R. S. Lull. 



3. Posterior and ventral anterior views of atlases of 



1. Equus caballus. 



2. Equus calobatus, n. sp. 



3. Equus scotti. 



About one- sixth natural size. 



4. Limb bones. 



1. Equus calobatus, n. sp., hind limb. 



2. Equus calobatus, n. sp., fore limb. 



3. Equus scotti. hind limb. 



4. Equus scotti, fore limb. 



One-sixteenth natural size. 



5. Cross sections of sacra. 



A. Equus calobatus. 



B. Equus scotti and E. caballus. 



One-fourth natural size. 



6. Auchenia hesterna, third upper molar, crown and side view. 



7. Auchenia hesterna, 1st phalanx, front and side view. 



8. Eschatius conidens, maxillary with alveolus of P 4 , the sole rem- 



nant of the premolar dentition, and M 1 and M 2 . 



9. Auchenia hesterna, scapula head. 



10. Eschatius conidens, scapula head. 



11. Auchenia hesterna, head of cannon-bone. 



12. Eschatius conidens, head of cannon-bone. 



13. ? Eschatius conidens, 1st phalanx of camel, showing unusual 



slenderness and dissymmetry. 



14. Pathologic camel phalanx. 



15. Normal camel phalanx, front and rear views. 



16. Canis dims, 1st phalanx. One-half natural size. 



17. Canis dirus, tibia, posterior view. 



18. Canis texanus, n. sp., holotype, ramus and dentition. 



19. C. ? priscolatrans, 1st upper molar. 



20. C. texanus, n. sp., paratype, 1st upper molar. 



21. C. temerarius, 1st phalanx. One-half natural size. 



22. C. temerarius, tibia. One-half natural size. 



23. C. texanus, n. sp., paratype, humerus, side and rear views. 



24. Platygonus compressus, fragment of ramus and tusk. Two-thirds 



natural size. 



All figures one-third natural size, unless otherwise indicated. 



