MUSTELA 419 



angular mastoid processes ; auditory bullae distinctly triangular in 

 outline ; inner lobe of upper carnassial functioning against 

 paraconid of lower carnassial ; interrelationships of teeth essen- 

 tially as in Mustela, but small premolars more robust and less 

 trenchant. 



Bemarks. — The sub-genus Putorius, with three species in the 

 Old World and one in America, appears to be the most sharply 

 defined of the three groups into which the genus Mustela is now 

 divided. No intermediate forms are known connecting it with 

 either Lutreola or true Mustela, and if none are found the group 

 will probably be regarded as a distinct genus. Two of the Old 

 World species occur in Europe, but only one comes within the 

 scope of the present work. 



MUSTELA PUTORIUS Linnseus. 



(Synonymy under subspecies.) 



Geographical distribution. — Europe from Great Britain east- 

 ward, and from the Mediterranean coast to central Scandinavia. 

 Eastern limit of range not known. 



Diagnosis. — Skull with wide brain-case and conspicuously 

 angular projecting mastoid region, the mastoid breadth decidedly 

 greater than distance from basion to palation ; auditory bullae 

 slightly longer than broad, triangular in outline ; size nearly 

 equal to that of the martens (head and body of adult male about 

 400 mm.) ; form slender, fur coarse, tail rather bushy, tapering : 

 colour buffy grey or yellowish overlaid with black, the under- 

 pays darker than back. 



External characters. — Form much as in the members of the 

 sub-genus Mustela, but appearing less attenuate on account of 

 the longer fur and somewhat bushy tail. Underfur rather dense 

 and woolly, about 25 mm. long in winter, 15 mm. in summer; 

 longer hairs coarse and loose, very different in quality from the 

 underfur and not concealing it, their length at middle of back 

 about 40 mm. in winter, somewhat less in summer ; tail about 

 one-third as long as head and body, rather bushy, its underfur 

 evident, the longer hairs about 30 mm. in length at middle, 

 decreasing in length toward tip so that the tail tapers noticeably 

 from basal half outward. Feet moderately long, more robust 

 than in true Mustela, the plantar and palmar tubercles larger, 

 bare in summer, furred in winter, the soles always thickly 

 furred ; claws of front feet about 6 mm. in length, rather 

 strongly curved and partly retractile, those of hind feet about 

 4 mm. long, slightly curved, not retractile. Head somewhat 

 flattened, muzzle rather wide ; eyes small ; ear low, rounded, 

 never conspicuously overtopping fur, its height from crown 

 seldom exceeding 15 mm. Mammae : i 4 — 4 = 8. 



Colour. — Feet, tail, chest and intercrural region blackish, rest 

 of body with long black hairs producing a clouded effect over 



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