CHARACTERS OP SCARTURUS AND OTHER JERBOAS. 



661 



The Rhinarmm and Mouth. 



In Zapus the rhinarium is well defined and marked by a 

 distinct vertical groove, formed by the thickened bulging upper 

 and inner margin of the nostrils. Above the thickening of the 

 upper rim there is a short transverse area. The area below 

 the rhinarium, extending from the nostrils to the edge of the 



Text-fio-ure 29. 



A. Head of Zapus Jiudsonianvs. 



B. „ Jacidvs jaculus. 



C. „ Scirtopoda orientcdis. 



D. „ Scarturus teh'ctdaef.i/lus. 



upper lip, is covered with shortei- hair than the rest of the 

 muzzle. There is no sign of a groove or ghiltrum dividing 

 the upper lip in the middle line. (Text-fig. 30, A.J" 



From Miller's description of the rhinarium of /Sicista loriger 

 (Cat. Mamm. Western Europe, p. 537, 1912), it seems that the 

 muzzle resembles in general features, at all events, that of Zapus, 



45* 



