CEICETUS 597 



BemarJcg. — The genus Cricetus is too easily recognizable 

 among the European groups of rodents to require any special 

 comparisons. As at present understood it is represented by a 

 single species. 



CRICETUS CRICETUS Linnaeus. 



(Synonymy under subspecies.)! 



Geographical distribution. — Central Europe from Belgium and 

 northern France eastward into Russia and Asia Minor. Eastern 

 limit of range unknown. 



Diagnosis. — Essential characters as in the genus ; size about 

 as in a large house rat, length of hind foot in adult 30 to 35 mm., 

 condylobasal length of skull 43 to 51 mm. ; underparts entirely 

 black in strong contrast with sides. 



External characters. — Form robust and heavy, suggesting a 

 house rat with short legs and rudimentary tail. Ear rather 

 large, orbicular, extending about to eye when laid forward ; a 

 slightly developed ridge behind meatus ; surface of ear well 

 clothed both externally and internally with fine hairs. Muzzle- 

 pad ill defined ; inner border of nostril swollen and projecting, 

 upper border notched ; a narrow median groove between nostrils 

 continuous below with broad naked and wrinkled median area 

 on upper lip. Cheek-pouches large, extending backward to 

 about level of ear, their openings entirely within the loosely 

 spreading lips. Feet moderately large, the claws stout, slightly 

 curved, those on front feet slightly exceeding those on hind feet 

 in size. Front foot with inner digit rudimentary, tubercular, 

 with minute flattened nail ; second digit slightly longer than 

 fifth and a little exceeded by fourth, this in turn by third, the 

 contrasts in length not very noticeable ; palm with five well 

 developed tubercles, of which the two posterior are largest, and 

 that at base of second toe smallest ; relatively to size of palm 

 the tubercles are large, leaving little space between them. 

 Hind foot with all five toes well developed, the innermost 

 extending to base of second, the outermost slightly longer, the 

 three middle digits sub-equal and longest ; tubercles six, all well 

 developed and of about equal size though rather small, not 

 arranged in pairs, the postero-internal lying distinctly behind 

 postero-external ; surface of sole hairy from heel to posterior 

 tubercles ; median area nearly to anterior tubercles distinctly 

 pubescent. Tail short but well developed, extending about to 

 tip of outstretched hind feet ; annulations ill-defined and 

 irregular, concealed by the thick covering of short hairs. 

 Mammre: p 2-2, i 2-2 = 8. 



Colour. — tipper parts a uniform light yellowish brown or 

 brownish buff, the exact shade usually something between the 

 wood-brown and ochraceous-buff of Ridgway though occasionally 

 with a russet or yellowish tinge, particularly on flanks, rump 



