250 Univcrsifij of California I't(hIicafio)ts in ZooJogij. [Vol.7 



liaird, in the original description ot* occidoiialis (1855, p. 

 385) gives the length of the head and l)ody as 10 inches (^ 

 253.9 mm.) and length of tail vertebrae 8 5/12 inches (or about 

 213 mm.). The single adult animal from the Pine Forest ^loun- 

 tains has a length of 207 and 170 mm., respectively, for the cor- 

 responding parts. Evidently our animal is smaller than the type 

 of Decide ntalis, approaching the measurements given by Elliot 

 in his Synopsis (1901, p. 163), which are: total length, 387mm.; 

 tail vertebrae, 165 ; hind foot, 42 ; ear, 31.5. The average measure- 

 ments of the two examples from the ^luseum collection are 

 respectively as follows : total length, 368 mm. ; tail vertebrae, 

 161 ; hind foot, 43 ; and ear, 30.5. The adult from Nevada 

 measures 377, 170, 41, and 27 (ear measured in dry skin, notch 

 to tip). The young animal has the posterior part of the sole of 

 the hind foot furred, the fur in the adult extending a much 

 shorter distance onto the sole. 



The Juvenal differs from the adult in the possession of smaller 

 dimensions (total length, 329, tail vertebrae, 148; hind foot, 45), 

 in much less bushy tail, the hair being short, in softer, shorter 

 hair dorsally, with more of a bluish coloration (the yellowish 

 ])rown hardly shows except on the upper side of the forelegs, and 

 posteriorly along the sides), and in the coloration of the tail, 

 which is gray dorsally, edged with white, instead of brownish 

 plumbeous. 



Distribution. — The adult female was collected July 16, at 

 an altitude of 6000 feet on Alder Creek; and the male juvenal 

 (no. 7892), at 6500 feet altitude on Leonard Creek, August 5. 



The present records are from a locality on the extreme mar- 

 gin of the range of occi(l< ntalis (Goldman, 1910, p. 96) and it 

 might be expected that the characters of the sixH-imens, although 

 nearer those of occidenfalis, would not be absolutely typical of 

 either species, and such is the case. 



The localities at which wood rats were taken by our party 

 wcic hardly above the l'i)i)er Sonoran life-zone, or if in Transi- 

 tion, only at the lowermost level of it. 



Habits. — We tra])ped very thoi'oughly for these wood rats 

 on rocky ridges of the higher parts of the range, but our efforts 

 were in every case attended with failure. What was our sur- 



