924 



Genus CITELLUS ()k(ui 



181G. Citellus Okcn, Lcbrb. dcr Ncaturgcsch., Th. in, Abth., ii, p. 824 



(citelltos). 

 1825. Spermopliil'iis F. Cuvier, Dents dcs Mammiferes, p. IGO {ci(cllus). 

 1827-34. Citillus Lichtenstein, Darstell. ncuer oder wcnig bekanntcr 



Siiugetb., pi. XXXI (citellus). 

 1857. Spcrmoj)hibis Blasius, SJiugetbiere Deutscblands, p. 275. 

 rj02. Citellus Allcu, Bull. Amer. Mus. Nat. Hist., xvi, p. 375, October 11, 



1902. 



Ti/pe i<pec}es. — Mus citellus Linn;eus. 



Geographical distribution. — Northern Hemisphere from 

 Hungary eastward through Asia and North America to the 

 central United States. 



Characters. — Strictly terrestrial Sciuridse of medium size and 

 slightly modified Sciurine aspect, the tail flattened but relatively 

 shorter and less bushy than in Sciurus ; cheek pouches present ; 

 skull more massive than in Sciurus, the brain-case much less 

 convex above, its depth rather more than twice that of rostrum ; 

 incisors sub-terete ; molars with cross-ridges and inner tubercle 

 relatively high, obscuring the basin-shaped form of crown, and 

 forming a conspicuous [J -shaped pattern in moderately worn 

 teeth ; anterior upper premolar well developed. 



Beuiarls. — Though the limits of the genus Citellus are not at 

 present well understood, owing chiefly to the difliculty of com- 

 paring the Old World and American forms, the group may be 

 regarded as containing about eight Pahearctic species, two of 

 which occur in central Europe. Remains of extinct membei-s of 

 the genus are found as far west as England. 



KEY TO THE EUROPEAN SPECIES OP CITELLUS. 



Back without distinct spots ; skull with incisive fora- 

 mina normal, their length greater than diameter of 

 alveolus of upper incisor (Hungary in general, and 

 eastward) C. citellus,]}. 924. 



Back with sharply defined whitish spots about 4 mm. in 

 diameter ; skull with incisive foramina very small, 

 their length about equal to diameter of alveolus of 

 upper incisor (Hungary cast of the Carpathians, and 

 eastward) C. suslica, p. 929. 



CITELLUS CITELLUS Linnfeus. 



1766. [Mus] citellus Linnseus, Syst. Nat. i, 12th ed., p. 80 (Austria). 

 1778. Mus citillus Pallas, Nov. Sp. Quadr. Glir. Ord., p. 19. 

 1857. S'pcrmophilus citellus Blasius, Saugethiere Deutscblands, p. 275. 

 1904. [Citellus'] citellus Trouessart, Catal. IMam. Viv. Foss., Suppl., p. 339. 

 1910. Citellus [Citellus) citellus Trouessart, Fauue Mamm. d'Europo, 

 p. 127. 



Type locality. — Austria. 



Geographical distribution. — From Silesia and Bohemia, east- 



