216 Proceedings of Indiana Academy of Science 



of mice taken the individual mice are quite active. Like the other species 

 of deer mouse their usual mode of progression is by jumping on all four 

 feet at once. Only rarely does one find tracks apparently made by 



FiK. 1. ('ouisc ol' )-!air(i's iJeor Aluuse, I'troviysrus mauirulatiis hiiirdii. m iliy sanil. 



walking, in which case what appear to be tail marks are sometimes 

 present. In the jumping mode of progression the tail doe.s not touch 

 the ground. There seemed to be a tendency for the animals to jump 

 along the same course or else for the same animal to jump back and 



Fig. 2. Footprints of Raiid's Deer Mouse, Pcroviysciis viajiiculattiti bairdii, in ilry 



sand. 



forth along it. The sand was often well marked by their tracks into 

 almost a runway, usually in a direction parallel to the axis of the low 

 dunes. 



The mammae are pectoral 1/1 inguinal 2/2=6. Of the four females 



