CHARACTERS OF SCARTURUS AND OTHER JERBOAS. 



665 



from the ear of Zapus, with the anterior flap concealed, as is 

 normally the case, by being folded inwards. 



Text-figure 31. 



A. Eav of Zapus hudsoniamis, expanded. 



B. The same, contracted. 



C. Base of ear of the same, with basal portion cut open between tragus 



and antitragus. 



D. The same of Scarturus tetradactijJns. 



E. The same of Scirtopoda orientalis. 



F. Expanded ear of Pedetcs coffer. 



G. Folded ear of the same. 



H. Base of the ear of the same, cut open. 

 I., infolded lamina of anterior border; t., tragus; at., antitragus; s., supratrngus ; 

 o., orifice of ear ; c, columnar process. 



In the Jaculidpe the ears vary greatly in length. In Eucho- 

 reities, the longest-eared form, they considerably overlap the tip 

 of the exceptionally long snout, when turned forwards--. ]n 



