Vol. 30, pp. 147-148 July 27, 1917 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



TWO NEW POCKET MICE FROM WYOMING, 

 BY E. A. GOLDMAN. 



In determining the status of pocket mice obtained in the 

 course of biological investigations in Wyoming, two undescribed 

 subspecies have been detected. One of these is a pallid repre- 

 sentative of Perognathus parvus ; the other a large, light-colored 

 form of Perognathus flavus, by whose discovery in the State the 

 known range of the species is materially extended northward. 



They are characterized as follows : 



Perognathus parvus clarus, subsp. nov. 



Type from Cumberland, Wyoming. No. 178,939, <? adult, U. S. 

 National Museum (Biological Survey Collection), collected by S. G. 

 Jewett, May 18, 1912. Original number 976. 



Geographic distribution.— Green River Valley in southwestern Wyom- 

 ing, and upper part of Snake River Valley in southeastern Idaho. 



General characters. — Similar to Perognathus parvus parvus but some- 

 what larger ; skull more massive ; color paler. Size and proportions about 

 as in P.p. olivaceus, but upperparts light buffy instead of light ochraceous 

 buffy ; lateral line less distinct. 



Color.— Upperparts in general light-buff, finely and rather inconspicu- 

 ously lined with black; buffy lateral line faint; white subauricular spots 

 prominent as in P. p. olivaceus; feet and underparts white ; tail brownish 

 along a narrow line above; white below. 



Skull. — As in P. p. olivaceus; larger, broader and more massive than 

 that of P. p. parvus, with mastoids distinctly larger and rostrum broader. 



Measurements.— Type: Total length, 181; tail vertebrae, 84; hind foot, 

 •1-1. Average of 7 adult topotypes: 172 (160-186) ; 91 (83-97) ; 22 (21-23). 



Skull (type): Greatest length, 25.4; greatest mastoid breadth, 13.4; 

 interorbital breadth, 5.6; nasals, 10; interparietal, 5.6x3; maxillary 

 toothrow, 3.9. 



Remarks.— The pallid coloration of Perognathus parvus clarus, shared 

 with Perognathus fasciatus litus, Perognathus callistus, Perodipus ordii 



3&-PROC. Biol. Soc. Wash.. Vol. 30, 1917. (147) 



