924 



KODEXTIA 



Genus CITELLUS Oken. 



181G. CitcUus Oken, Lchrb. der Naturgcscb., Th. iii, Abth., ii, p. 824 



{citcUus). 

 1825. Spcrmophihis P. Cuvier, Dents cles jMammiforcs, p. IGO {citellits). 

 1827-34. Gitillus Lichtenstein, Darstell. ncucr oder wcnig bekannter 



Siiugotb., pi. XXXI (citcUus). 

 1857. Spcrmophilus Blasius, Siiugetbicrc Dcutscblands, p. 275. 

 l'J02. Citdlus Allen, Bull. Amer. Mus. Nat. Hist., xvi, p. 375, October 11, 



1902. 



Tjipe xjx'cics. — Mhs ritelliig Linn;i'us. 



Gcor/rapliical dhirihitiion. — Northern H'eniispliero fri)ni 

 Hungary eastward through Asia and North America to the 

 central United States. 



Characters. — Strictly terrestrial Srliiridie of medium size and 

 slightly modified Sciurine aspect, the tail flattened but relatively 

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

 skull more massive than in ScinrKS, 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 (Jshaped pattern in moderately worn 

 teeth ; anterior upper premolar well developed. 



Hemarls. — Though the limits of the genus CitrJhi)- are not at 

 present well understood, owing chietly to the difficulty of com- 

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

 regarded as containing about eight Pala-aix'tic species, two of 

 which occur in central Europe, llemains of extinct members of 

 tlie genus are found as far west as England. 



KEY TO THE EUROPEAN SPECIES OP CITELLUS. 



Back Nvitbout distinct spots ; skull with incisive fora- 

 mina normal, their length greater than diameter of 

 alveolus of upper incisor (Hungary in general, and 

 eastward) C. citcUus,]). 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 east of the Carpathians, and 

 eastward) C. suslica, p. 929. 



CITELLUS CITELLUS Liniueus. 



1766. [iLTi^s] citcUus Linnfeus, Syst. Nat. i, 12th ed., p. 80 (Austria). 

 1778. M21S citillus Pallas, Nov. Sp. Quadr. Glir. Ord., p. 19. 

 1857. Spcrmophilus citcUus Blasius, Saugethiere Deutschlands, p. 275. 

 1904. [CitcUus'] citcUus Trouessart, Catal. Mam. Yiv. Foss., Suppl., p. 339. 

 1910. CitcUus [CitcUus) citcUus Trouessart, Fauna Mamm. d'Europe, 

 p. 127. 



Type localiiy. — Austria. 



Geographical distribution. — From Silesia and Bohemia, east- 



