PEROMYSCUS. 17 1 
Fig. 33. PEROMYSCUS FURVUS. 
No, 10768 Am. Mus. Nat. Hist. Coll. Twice nat. size. 
UPPER TOOTH ROW. LOWER TOOTH ROW. 
Enlarged to times. Enlarged to 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 175 
b.” Under parts buffy, ears small. 
Be SMT i Gyo tk clee er P. musculus 1758 
