Illustrations xi 
FIG. PAGE 
27. Moki Kangaroo Rat, Perodipus longipes, dorsal 
view of skull ...... 73 
28. Mountain Kangaroo Rat, Perodipus montanus . 74 
29. Mountain Pocket Gopher, Thomomys fossor, 
face showing cheek pouches ... 82 
30. Mountain Pocket Gopher, Thomomys fossor . 83 
31. Chestnut-faced Pocket Gopher, Cratogeomys 
castanops, skull, showing dentition . . 91 
32. Saguache Vole, Microtus pennsylvanicus modes- 
tus, skull, showing dentition ... 94 
33. Cantankerous Vole, Microtus mordax . . 99 
34. Muskrat, Fiber zibethicus, skull, showing den- 
tition ....... 105 
35. Nest of Bailey's Wood-rat, Neotoma floridana 
baileyi . . . . . . .112 
36. Bailey's Wood-rat on tree cactus . . .113 
37. Bailey's Wood-rat, female with two young . 114 
38. Nest of Gale's Wood-rat, Neotoma fallax . .115 
39. Mountain Rat, Neotoma cinerea orolestes, skull, 
showing dentition . . . . .117 
40. Monntain Rat, Neotoma cinerea orolestes . 118 
41. Nest of Mountain Rat . . . . .119 
42. Tawny Deer-mouse, Peromyscus maniculatus 
rufinus ....... 129 
43. Nebraska Deer-mouse, Peromyscus m. nebras- 
censis, skull, showing dentition . . .131 
44. Tawny and True's Deer-mice, picture of dead 
specimens showing relative size of ears . 136 
