Vol. XVII, pp. 127-128 June 9, 1904 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



TWO NEW POCKET MICE OF THE GENUS 

 PEROGXATHUS. 



BY WILFRED H. OSGOOD. 



Several hundred specimens of pocket mice have been secured 

 by field parties of the Biological Survey since the publication of 

 the last revision of the genus Perognathus.^ Among these are 

 many which serve to increase the knowledge of the distribution 

 and relationships of the various species and subspecies. The 

 new material also indicates that two well-marked subspecies are 

 still unnamed. They may be knoAvn as follows: 



Perognathus flavescens perniger subsp. nov. 



Type from Vermilion, South Dakota. Young-adult female, No. 57,725, 

 U. S. National Museum, Biological Survey Collection. Aug. 22, 1889. 

 G. S. Agersborg. 



Charnderit. — Size, proportions, and skull much as in P. flavescens ; color 

 of upperparts chiefly intense black ; underparts chiefly ochraceous buff. 



Color. — Median dorsal region intense black or brownish black to roots of 

 hairs; sides and head mixed black and ochraceous buff; ears brownish 

 black very narrowly edged with buffy ; inferior subauricular spot bright 

 buff, superior one nearly obsolete ; lateral line ochraceous buff, broad and 

 sharply contrasted ; underparts rich ochraceous buff except chin and a 

 narrow stripe on throat and breast, which are white; tail dusky above, 

 whitisli below, narrowly buffy Jon sides ; feet buffy, toes paler. 



Skull. — As in P. Jiavescens. 



Measurements. — Type: Total length, 140; tail vertebrae, 68; hind foot 



(dry), 17. 



* North American Fauna, No. 18, September 20, 1900. 



21— Proc. Biol. Soc. Wash. Vol. XVII, 1904. (127) 



