242 FIELD COLUMBIAN MUSEUM ZOOLOGY, VOL. III. 



38.5; ear, 12. Skull: total length, 37.3; Hensel, 30; zygomatic 

 width, 19; interorbital width, 10; length of nasals, 10.5; palatal 

 length, 12; length of upper tooth row, 7; length of mandible, 22; 

 length of lower tooth row, 7. 



Strange as it may appear, this form has its nearest ally in C. I. 

 peninsula from Lower California, differing from that race in the char- 

 acters given above. The general dark coloring and the vinaceous 

 hind foot with its smaller measurements readily serve to distinguish it 

 from C. leucurus. The hind foot of the type exhibits the greatest 

 dimension, and the average of this member in the series before me 

 would be much less, as a number measure only 36, some even 35.5 

 mm. It seems to supplant the C. leucurus of the Mohave Desert, 

 and is dispersed through the mountain region between Keeler 

 and Death Valley. Keeler examples, like other mammals from that 

 locality, exhibit the deepest colors, and the race appears to be strongly 

 marked. 



Citellus *chlorus. Sp. nov. 



Type locality: Palm Springs, Riverside County, California. 



Geogr. distr.: Riverside and San Diego counties, California. 



Gen/, char.: Size about equal to that of C. terelicaudus, but color 

 entirely different. Skull rather stout and heavy; tail long. 



Color: Entire upper parts and sides olive gray with a brownish 

 sheen in certain lights; upper part of arms and thighs olive gray; 

 entire under parts grayish white; hands brownish, feet whitish; tail 

 above, basal half like back, slightly more brownish, apical half black- 

 ish mixed with brown and edged with white; beneath pale brown, 

 margined very narrowly with black and fringed with white; ears very 

 small, blackish. 



Measurements: Type. Total length, 255; tail, 100; hind foot, 37; 

 ear, 8. Extremes: total length, 230-255; tail, 88-100; hind foot, 

 35-37; ear, 7-8. Skull: total length, 32; Hensel, 30; interorbital 

 width, 8; zygomatic width, 22; width of brain case, 18; length of 

 nasals, 8; palatal length, 17; length of upper tooth row, 7; length of 

 the half of lower mandible, angle to tip of incisors, 24; length of lower 

 tooth row, 6.5. 



This species of Citellus is not like any of the other members of 

 this particular group. In the entire absence of spots it resembles its 

 relatives, but is at once distinguished from all others by its peculiar 

 coloring. 



* %'t.opotT pale. 



