272 VERTEBRATE ANIMALS OF THE UXITED STATES 



Subspecies of B. astutus 



B. a. Havus Rhoads. Size smaller; color blackish on the back, 

 tawny on the sides: central and southern Texas to California; southern 

 Colorado; southern Utah. 



B. a. oregonus Rhoads. Dorsal region intensely black ; color beneath 

 brownish yellow; western Oregon and northern California. 



Family 5. Mustelidae. — Weasels, otters, skunks, etc. Body usu- 

 ally elongate; legs short; feet plantigrade or digitigrade; toes 5-5; 

 claws never fully retractile; tail usually long; tongue with rasping 

 papillae; anal glands usually present which secrete a fetid liquid; color 

 usually uniformly dark brown or black and white: numerous species; 

 savage, carnivorous or omnivorous animals found in all the geographical 

 regions except the Australian, and most numerous in the Temperate 

 and Boreal zones, many being valuable fur-bearing animals; about 11 

 genera and 65 species in North America, about 45 species occurring in 

 the United States, grouped in 6 subfamilies. 



Key to the Subfamilies of Mustelidae 



ai Claws partly retractile. 



bi Feet digitigrade; body slender i. Miistelince. 



b2 Feet plantigrade; body stout 2. Giilonince. 



ao Claws not retractile. 



bi Toes not fully webbed. 



Ci Last upper molar very large and quadrangular; skunks. . . .3. Mephitince. 



C2 Last upper molar triangular; badgers 4. TaxidiincB. 



hi Toes fully webbed. 



Ci Incisor teeth 3-3; otters 5. LutrincE. 



C2 Incisor teeth 3-2; sea otters • 6. EnhydrincE. 



Subfamily i. Mustelinae. — Weasels, martens and minks. Body 

 slender; toes short and partly retractile: 3 genera. 



Key to the Genera of Mustelinae 



ai Teeth 38; feet digitigrade i. Maries. 



ao Teeth 34; body slender and small; weasels (Fig. 158) 2. Mustela. 



I. Martes Pinel (Mustela L.). Martens. Body elongate and 

 slender; tail long and bushy; ears short; dentition ^/^, i/i, 4/4, 1/2 

 (Fig. 156) ; toes partly webbed; claws small, sharp and partly retractile: 

 8 species in North America, about 3 in the United States. 



Key to the United States Species of Martes 



ai Body slender. 



bi Light-colored cheek patches present M. americana. 



bj No light-colored cheek patches present M. caurina. 



a.2 Body stout M- pennanti. 



