xiv AMERICAN MESOZOIC MAMMALIA 



40. Docodon su-perus. Right crown view, type. 9^ 



41. Multituberculates. Lower incisors. 104 



42. Multituberculates. Upper premolars. 106 



43. Didelphid upper molars. 119 



44. Pediomys sp. Left half of palate. Superior and inferior views. 120 



45. Lance didelphid upper molars. 121 



46. Lance didelphid and ?insectivore. 123 



47. Thlaeodon fadanicus, upper jaw fragment, lower jaw and crown view of lower teeth, 



type specimen. 124 



48. Eodelfhis cutleri, lower jaw, external view, and crown view of teeth. 128 



49. Eodelfhis cutleri, fragments of skull, side and under views. 129 



50. Lower molars of Lance didelphids. 132 



51. Lance pediomyine. Fragment of right lower jaw with two molars. 133 



52. Lance pediomyine. Fragment of left lower jaw with two premolars. 134 



53. Gyfsonictofs hyfoconus. Upper cheek teeth. 137 



54. Telacodon laevis. Part of right lower jaw with last three premolars, external view, 



type. 138 



55. Batodon tenuis. Part of left lower jaw, external view, type. 139 



56. Upper molars in the six Mesozoic orders of mammals. 140 



57. Lower molars of Mesozoic mammals. 14^ 



58. Suggested relationships of the major groups of mammals. 143 



59. Map. Known occurrences of Mesozoic mammals. 148 



60. Map. Known occurrences of Mesozoic mammals in North America. 149 



61. Tentative correlation of the mammal -bearing formations of the Mesozoic and of the 



principal Paleocene mammal horizons. 150 



62. Diagram showing the relative positions in time of the known Mesozoic mammalian 



faunas and the approximate relative dates of some of the major events in mam- 

 malian history. 158 



PLATES 



L Ctenacodon '■73 



IL Ctenacodon ^75 



III. Ctenacodon '^^^ 



IV. Psalodon ^79 

 V. Psalodon 181 



VI. Tathiodon 183 



VII. Archaeotrigon, Dryolestes 185 



VIII. Dryolestes, Laolestes 187 



IX. Laolestes 189 



X. Laolestes 191 



XL Laolestes, Amblotherium I93 



XII. Amblotherium I95 



XIII. Herpetairus, Melanodon I97 



XIV. Melanodon ^99 

 XV. Melanodon, Malthacolestes 201 



XVI. Euthlastus, Pelicopsis, Docodon 203 



