GENUS SYLVILAGUS 153 



Genus Lepus Linnaeus. 



Interparietal not distinct in adults ; supraorbital usually broadly 

 expanded, subtriangular in outline; second to fifth cervical ver- 

 tebras longer than broad ; median carina on dorsal surface ; hind 

 foot, in our forms, five inches or over. 



Dental formulaI. 2/1 ; Pm. 3/2 ; M. 3/328. 

 Key to Species of Lepus. 



1. Length of ear from skull to tip less than 3.75 inches; 

 total length 17.50 to 18.50 inches; hind foot five inches 

 or more. 



Minnesota Varying Hare. 

 Lepus americrtmis phaeonotus. p. 130 



Length of ear from tip to skull 3.75 inches or more; 



total length more than 20.00 inches 2 



2. Tail entirely white above and below; rump whitish in 

 winter, similar to rest of back in summer; total length, 

 24.00 inches. 



White-tailed Jack Rabbit. 

 Lepus townsendi campanius. p. 131 



Tail whitish below, the upper side marked with a black- 

 ish band extending backward from rump; rump patch 

 large, gray; total length, 23.00 inches. 



Great Plains Jack Rabbit. 

 Lepus calif ornicus melanotis. p. 133 



Genus Sylvilagus Gray. 



Interparietal distinct in adult; supraorbital prominent, the post- 

 orbital process more slender and pointed than in Lepus; posterior 

 notch usually narrowed or obliterated on account of union of post- 

 orbital with skull ; second to fourth cervical vertebrae broader than 

 long; no carina on dorsal surface; one annual molt; hind foot, in 

 our representative, about four inches. 



Dental formula^-L 2/1 ; Pm. 3/2 ; M. 3/3=28. 



A single form occurs in Iowa. 



Mearns' Cottontail. 

 Sylvilagus floridanus mearnsi. p. 134 



