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r>ULLETTN 5fi, UNITED STATER NATTONAE MUSEUM. 



liiriiril (I ml jiii'asiirctiinit.f of 31 specimens of OloxjurniDpIii/n.^ hfrcln'i/l — Continued. 



Genus CITELLUS Oken (181( 



CifeUus Oken, Lehrbuch der zoologie, II, 181(5, p. 842. 

 Xat. Hist., XVI, p. :^7o, Oct. 11, 1902. 



-Alle.v, Bull. Am. Mu.s. 



Type. — Mvi< clteUu^i Linnanis. 



Size medium or small. Form varyino- from stout or .squirrel-like 

 to slender and weasel-like. Tail variable. Cheek-pouches always 

 present, and larg-e. Maims with four well-developed toes and a rudi- 

 mentary thuml), of which the claw may be either present or absent. 

 Skull lighter than in Cynomys, but more strongly built than in Seiurus 

 or /u/t/a/t/'a.s., and with the post-orbital processes slender and directed 

 backward and downward; plane of the molar turned outward; zygo- 

 matic arches spreading. Upper premolars two, but the first premolar 

 simp]}' rounded and single rooted, never more than about one-third of 

 the size of the second. Character of the pelage and pattern of colora- 

 tion variable. 



Subgenns ICTIDOMYS Allen. 



Ears generally small, sometimes rudimentary; tail long, cylindrieal, or narrow 

 and flattened, or quite broad, with the hairs one-half to three-fourths the length of 

 the body; skull very long and narrow; first upper premolar usually rather small, 

 and the dentition not heavy. Species, S. iereiicmidux, S. me.iicanus, S. Indecem lineatus, 

 S. franklini. (J. A. Allen. «) 



« Monographs of North American Rodentia, 1877, p. 821. (See Merriam, Science, 

 n. s., II, p. 418, September 27, 1885.) 



