MUSTELA 



383 



Brown of sides not encroaching on yellowish 

 or whitish of underparts, the line of 

 demarcation straight ; upper lip wholly 



or partly white M. erminea, p. 385. 



Eegion extending from front of rostrum to 

 and including postorbital processes 

 relatively broad and short ; size below 

 the maximum for the European races ; 

 condylobasal length of skull in adult 

 males, 43 • 4 to 48 '6 mm., mandible in 

 adult males, 23 to 26 • 4 mm. (Scandi- 

 navin Peninsula, except extreme south 



of Sweden) M. t. erminea, p. 387. 



Begion extending from front of rostrum 

 to and including postorbital processes 

 relatively narrow and long ; size maxi- 

 mum for the European races ; condy- 

 lobasal length of skull in adult males, 

 47 to 52 - 5 mm., mandible in adult 

 males, 25 to 30 mm. 

 Zygomatic arches broadly spreading 

 (ratio of zygomatic breadth to con- 

 dylobasal length about 59) ; posterior 

 extension of palate unusually short 

 and broad (Islands of Islay and Jura, 



Scotland) M. e. ricfiue, p. 397. 



Zygomatic arches moderately spreading 

 (ratio of zygomatic breadth to condy- 

 lobasal length about 54) ; posterior 

 extension of palate not unusually 

 short and broad. 

 White winter ooat normally assumed ; 

 condylobasal length of skull in 

 adult male seldom over 50 mm. ; 

 in adult female seldom over 

 45 mm. ; upper carnassial not 

 enlarged and thickened (Conti- 

 nental Europe from southern 

 Sweden to the Alps and Pyrenees) M. e. sestiva t p. 389. 

 White winter coat normally not 

 assumed ; condylobasal length of 

 skull in adult male often over 

 50 mm. ; in adult female often over 

 45 mm. ; upper carnassial enlarged 



and thickened (Great Britain) M. *. stabilis, p 390. 



Tail without conspicuous black terminal area, 

 though a tuft of black or blackish hairs 

 may be present in pencil ; skull with ros- 

 trum usually wider than interorbital 

 region ; condylobasal length of skull, except 

 in specimens from the Mediterranean 

 region, often less than 40 mm. in males, and 

 34 mm. in females ; hind foot (except in 

 M. africana) usually less than 41 mm. in 

 males and 25 mm. in females (Weasels). 

 Size about as in the smaller stoats, condy- 

 lobasal length of skull in adult male, 

 48 to 50 mm., mandible in adult male 

 about 28 mm., its depth at front of car- 

 nassial, 4 • 5 to 5 mm. ; tail nearly one-half 

 as long as head and body (africanus 

 group). 



