li)8 Dixon — A New Harvest Mouse from California. 



Color. — Hairs on back extensively tipped with black which gives the 

 dorsal surface a much darker appearance than in R. longicatida. Sides 

 of nose brownish black. Lips black. Sometimes a white spot on chin. 

 Feet are of a purple tint during life, and are very much darker, both above 

 and below, than in R. longicauda. The toes of the front feet are pure 

 white during life. The tail is very indistinctly bicolored, if at all. There 

 is a decided fulvous spot at the anterior base of the ear, which is a great 

 deal darker than in R. longicauda. The underparts are a bright fulvous 

 which contrasts strikingly with the grayish white underparts of R. longi" 

 cauda. 



Measurements. — A series of twenty-one R. ravirentris from Redwood 

 City, average: length, 180.7 (120-142); tail, 04.8 (50-74); hind foot, 10.0 

 (15-18); ratio of tail to total length, 49.5%. A series of four from 

 Palo Alto, Santa Clara County, Calif., average: length, 130.2 (121-139); 

 tail, 08.5 (58-08) ; hind foot, 1(1.7 ( 16-17). A single specimen from Elm- 

 hurst, near Oakland, measures: length, 140; tail, 70; hind foot, 17. 



A skull, number 158, $ , in my collection measures: basal length, 16.2; 

 nasals, 0.0; zygomatic breadth, 0; alveolar length of series of upper 

 molars, 2.9. This skull is possibly a little smaller than the average. 



Remarks. — This form is distinguishable from R. longicauda which in- 

 habits the foothills surrounding the bay, by its much denser fur, which 

 is darker both at the base and at the tips. The feet are very much darker 

 than in the upland form, as are also the ears. The tail is not distinctly 

 bicolored, as in R. Idhgicauda, and the red belly is very noticeable in 

 comparison. 



