PEROMYSCUS. 



171 



FIG. 33. PEROMYSCUS FURVUS. 



No. 10768 Am. Mus. Nat. Hist. Coll. Twice nat. size. 



UPPER TOOTH ROW. LOWER TOOTH ROW. 



Enlarged 10 times. Enlarged 10 times. 



KEY TO THE SPECIES AND SUBSPECIES. 



A. Size small, not over 190 mm. 



a. Tail equal to or less than half the length of 

 the body and head, 

 a/ Above drab gray. 



a." Under parts white, ears large P. tiburonensis 



b." Under parts buffy, ears small. 



a/" Smaller . . .P. musculus 



175 



175 



