CONTENTS. 



VOLUME IV. PART I. 



No. PAGE. 



ORDER I. MARSUPIALIA MARSUPIALS. 



1 . Didelphyidae Opossums i 



ORDER II. EDENTATA EDENTATES. 



2. Bradypodidae Sloths 19 



3. Myrmecophagidas Ant-eaters 24 



4. Dasypodidae Armadillos 31 



ORDER III. SIRENIA SIRENIANS. 



5. Manatidas Manatees 36 



ORDER IV. CETACEA CETACEANS. 



6. Balaenidae Baleen Whales 39 



7. Physeteridae Sperm Whales 44 



8. Delphinidae Dolphins, Porpoises, etc 48 



ORDER V. UNGULATA HOOFED QUADRUPEDS. 



9. Tagassuidas Peccaries 61 



10. Cervidaa Deer 68 



n. Antilocapridae Prong-horn Antelope 81 



1 2. Bovidse Cattle, Sheep, etc 83 



13. Tapirida? Tapirs 87 



ORDER VI. RODENTIA RODENTS. 



14. Sciurida3 Squirrels 90 



15. Castoridas Beavers 159 



1 6. Muridae Rats, Mice, Voles 162 



17. Geomyidae Pouched Rats 309 



1 8. Heteromyidae Kangaroo Rats, Pocket Mice 341 



19. Octodontidae The Octodonts 382 



20. Erethizontidae Porcupines 397 



21. Dasyproctidae Agoutis, Pacas 403 



22. Leporidae Hares, Rabbits 411 



xiii 



