REFERENCES TO THE PLATES. 463 



Fig. 5. Third molar of the left side, of the same individual. 



Figs. 6-19. HiPPAEiON sPECiosuM. See page 282. 



Fig. 6. First molar of the left side. 



Figs. 7-10. The specimens apparently from the same individual : Figs. 7, 9, 10, the first, third and 

 fourth molars of the left side ; Fig. 8, the second molar of the right side. 



Fig. 11. Second molar of the left side. Fig. 12. Fourth molar of the left side. 



Fig. 13. Fourth molar of the right side. Figs. 14, 1.5. Fourths, or fifths, of the right side. 



Fig. 16. Fourth or fifth of the left side. Specimen from Bijou Hill. 



Fig. 17. Fourth molar of the right side, the inner part restored. Specimen from Washington Co., 

 Texas. 



Figs. 18, 19. Fourth and fifth molars of the right side, both partially restored. Specimens from 

 Bijou Hill. 



Figs. 20-24. HiPPAEiON affine. See page 286. The specimens, except the last one, ajjpear to 

 have been derived from the same individual. 



Fig. 20. Second molar of the right side. Figs. 21-23. Third, fourth and fifth molars of the left side. 



Fig. 24. Last molar of the left side. 



Figs. 25-30. HippAEipN geatum. See page 287. 



Fig. 25. First molar of the right side. Fig. 26. Last molar of the right side. 



Fig. 27. Second or third molar of the right side. 



•Figs. 28, 29. Last molars of the right and left sides, with the triturating surfaces only partially 

 worn across. 



Fig. 30. Fifth molar of the right side. 



Figs. 31-38. HippAEiON, undetermined species. See page 289. 



Figs. 31, 32. Second and third molars of the right side. 



Fig. 33. Second molar of the left side. 



Fig. 34. First molar of the right side, apparently of the temporary series. 



Fig. 35. Second or third temporary molar of the right side. 



Fig. 36. First temporary molar of the right side. 



Figs. 37, 38. First and third temporary molars of the left side, apparently from the same individual. 



Figs. 39-48. Protohippus placidus. See page 277. 



Fig. 39. Last molar of the left side. Fig. 40. First molar of the left side. 



Fig. 41. First molar of the right side, apparently of the temporary series. 



Fig. 42. First molar of the left side, apparently temporary, and much worn. 



Figs. 4.3-45. Fourth or fifth molars of the right and left sides. 



Fig. 46. Second or third right molar, apparently temporary, and much worn. 



Fig. 47. Second or third right molar. 



Fig. 48. Second or third left molar, apparently temporary. 



Figs. 49-53. Merychippus insignis. See page 296. 



Fig. 49. Fourth molar of the right side. Fig. 50. Last molar, slightly worn, of the same side. 



Figs. 51-53. Specimens from Washington Co., Texas. 



Fig. 51. Sixth molar of the left side. 



Fig. 52. Slightly worn seconder third right molar. 



Fig. 53. First molar of the right side. 



Figs. 54-56. Merychippus mieabilis. See page 299. 



Fig. 54. Third temporary molar of the right side. 



Figs. 55, 56. Last molars of the right and left sides. 



