124 Proceedings of the Biological Society of Washington. 



time the specimens were received read: " Male received same date; some 

 larger, much darker on the back and deeper, brighter yellow on the 

 belly." 



Vlustela campestris sp. nov. 



Type, adult d\ skin and skull No. 171,490, IT. S. National Museum, 

 Biological Survey Collection, from Beemer, Nebraska; collected April 18, 

 1911, by Grover Sharp. 



General characters. — Similar to Mustela rixosus in color but slightly 

 paler; white of the underparts more extensive than in rixosus ami 

 encroaching upon the fore feet; toes of both front and hind feet white. 



Color. — Upper parts uniform Prouts brown, slightly darkened on the 

 face; tail same color as back, with a few white hairs in the tip; ventral 

 parts white. 



Cranial characters. — Skull about the size of that of rixosus, but narrower 

 postorbitally ; brain case narrower than in rixosus ami depressed anteri- 

 orly; palate narrower than in either rixosus or allegheniensis; postpalatal 

 notch short and narrow; audita! bullae natter and less angular than in 

 rixosus, and the region between the audital bulla and the glenoid fossa 

 less inflated. 



Measurements. — Type cT, flesh measurements of skin by collector: total 

 length, 184; tail vertebrae, 32; hind foot, 19. Skull of type: condylo- 

 basal length, 30.9; zygomatic breadth, 15; postorbital constriction, H.4; 

 interorbital constriction, <>.2; maxillary tooth row, 7.1; mandibular 

 tooth row, 7.9. 



Remarks. — The description of this weasel is based upon a single speci- 

 men which was sexed "female" by the collector, but which, judging 

 from cranial characters, is undoubtedly a male. Additional specimens 

 from other localities may possibly show intergradation with rixosus or 

 allegheniensis. 



