CONTENTS. 



Page. 



Introduction 5-7 



.Subjxen us Putorius (the ferrets) 7-9 



Subgeuus Ictis (the weasels) 9 



List of North American weasels -. 10 



Descriptions of species f 10-32 



Table of cranial measurements 33 



ILLUSTRATIONS. 



(All natural size.) 



PLATES. 



Frontispiece. Heads of Black-footed Ferret and Bridled Weasel. 



1. Skulls of Putoriitx nigripes and /'. putorius. 



2. Skulls of Putorius arcticus, alascensis, cicognani, streatori, and risosus. 



3. Skulls of Putorius frcnatus, longicauda, and tropicalis. 



4. Skulls of Putorius noveboracensis, washingtoni, and peninxuln . 



5. Skulls of Putorius longicauda, cicognani, noveboracensis, rixosus, ptninyulir, and 



arcticus. 



TEXT FIGUKES. 



1. Putorius nigripes, $ old. Trego County, Kaus. 

 2,3. Putorius cicognani, $ ad. Elk Itiver, Minnesota. 

 4-6. Putorius noveboracensis, <$ ad. Adiroudacks, New York. 

 7-9. Putorius longicauda, $ ad. Fort Sisseton, S. Dakota. 

 10, 11. Putorius longicauda upadix, 9. Elk River, Minnesota. 

 12-14. Putorius arlzoncnsis, $ ad. Boulder County, Colo. 



15. Putorius frenatus, 9 ad. Cofre de Perote, Vera Cruz, Mexico. 



16. Putorius tropicalis, 9 ad. Jico, Vera Cruz, Mexico. 



4 



