CONTENTS. 
PREFACE 
CONTENTS 
Maps ILLUSTRATING THE DISTRIBUTION OF SPECIES AND SUB- 
SPECIES BELONGING TO THE GENERA REPRESENTED WITHIN 
ouR LIMITS IN THE EASTERN UNITED STATES AND SOUTHERN ' 
CANADA 
INTRODUCTION 
Tue OssEuS SYSTEM 
Skull, 13; Teeth, 13; Vertebral Column, 15; Pelvis, 1 e Ribs, 
15; Sternum, 15; Scapula, 16; Clavicle, 16; Limbs and Feet, 16. 
ANATOMICAL AND PHYSIOLOGICAL CHARACTERS IN GENERAL 
Tegumentary Structures . 
Hoofs, Claws and Nails, 18; Hair, 18; Odor- earings Glands, 
IQ. 
Circulatory and Digestive Systems . 2 ae 
Heart, 20; Lungs, 21; Blood, 21; Stomach and Intestinal 
Canal, 22; Liver, 23. 
Urinary Organs 
Reproductive Organs 
Mammary Glands 
Nervous System and Organs of Sense 
Brain, 24; Spinal Chord, 24; Sense of Touch, 24; Sight, 25; 
Smell, 26; Hearing, 26; Taste, 26. 
TAXONOMY AND CLASSIFICATION 
SUBCLASSES, ORDERS AND SUBORDERS OF eve Mammals . 
Ciassiriep List or MAMMALS oF ILLINOIS AND WISCONSIN 
How to Estimate THE AGE oF A MAMMAL 
How to Measure A MAMMAL 
LiFE ZONES 
KeryY TO THE ORDERS AND FAMILIES REPRESENTED WITHIN OUR 
Limits 
Key to the Orders 
Key to the Families 
OrpeR MarsupiALiA. MARSUPIALS 
Family Didelphiide. Opossums 
3 
19 
23 
23 
24 
24 
27 
28 
30 
37 
37 
38 
41 
41 
41 
49 
51 
