Vol. V] TAYLOR— NEW SUBGENUS OF PHENACOMYS \2,\ 



(5) Tuberculation of feet and the number of mammas 



A young example of Phenacomys longicaudiis (No. 20658), 

 preserved in alcohol, has five tubercles on the fore feet; the 

 reduction of the thumb to a small tubercle makes the fore feet 

 appear ^o have an additional tubercle. The hind feet are six- 

 tuberculate. 



Longicaudiis has two pairs of mammae placed far back on 

 the belly. The only reference to the number of mammae in the 

 genus Phenacomys which I have been able to find in the 

 literature is that of Miller (1897b, p. 22), in which a female of 

 P. latimamis is stated to have eight mammae, four pectoral 

 and four inguinal. A difference in numxber of mammae may 

 characterize the two subgenera. 



(6) The type of Phenacomys longicaudiis True 

 This specimen has been several times described and the 

 condition of its skull commented on (True, 1890, p. 303; 

 Miller, 1897a, p. 85 ; Merriam, 1901, p. 126; Lyon and Osgood, 

 1909, p. 96). Tooth pattern in No. 19974 of our series from 

 Mendocino City practically the same as in the type ; and exter- 

 nal characters show clearly that specimens in our collection 

 are almost identical with the type. 



(7) The specimen from Meadows, Lane County, Oregon 



Miller (1897a, p. 85) has described the aberrant speci- 

 men from Meadows, Lane County, Oregon ( '^ , No. -j^ 

 U. S. Nat. Mus., Biol. Surv. Coll., taken April 13, 1891), in 

 the following words : "Head, back and sides pale yellowish 

 drab, the fur light bluish plumbeous at base and sprinkled with 

 inconspicuous dark hairs ; belly grayish white, the bluish bases 

 of the hairs showing through irregularly; tail indistinctly 

 bicolor, light slaty gray above and at tip, whitish mixed with 

 gray below; feet silvery white." Merriam (1901, p. 126) 

 refers to the same specimen as being pale buffy fulvous, and 

 remarks that it seems to be a partial albino. 



(8) Pelages 

 Specimens are available representative of every month in 

 the year except September and December. Examples with 

 the longest hair were collected during the winter months 

 (notably No. 19130, taken January 6, and No. 19174, 

 March 27). 



