140 Proceedings of the Biological Society of Washington. 



Skull. — Similar to that of peninsulae, with broad braincase, widely 

 spreading zygomata, large post-orbital processes, broad and much inflated 

 audita! bullae, broad inter-pterygoid fossa and heavy molars. The bullae 

 are of essentially the same shape as those of peninsulae but are not quite 

 so high. 



Measurements. — Type ( d 71 ad.): total length, 420; tail vertebrae, 140 

 hind foot, 50. Skull: occi pi to-nasal length, 48; basilar length, 46.8 

 palatal length, 21.6; mastoid breadth, 25.3; zygomatic breadth, 29.3 

 breadth across post-orbital processes, 14; least interorbital breadth, 9 

 audital bullae, 15 x 7.0; width of inter-pterygoid fossa, 3.5. 



Remarks. — On account of the scarcity in collections of Mustela penin- 

 sulae peninsulae , the range of color variation in that race is not known. 

 The two winter specimens before me, however, differ widely, the palest 

 one (No. 9379, Coll. Acad. Nat. Sci. Phila., Tarpon Springs, Florida) 

 being about Verona-brown (of Ridgway), the other a much darker 

 shade of brown. Both are darker and browner than the type of olivacea. 

 The summer pelage of peninsulae is not definitely known, but a worn 

 specimen from Hernando Co., Florida, is decidedly lighter than the 

 specimens of olivacea from Leigh ton. The latter do not differ much in 

 color of the upperparts from certain specimens of noveboracensis, but the 

 underparts are a duller shade of yellow. 



This weasel may be instantly recognized as distinct from Mustela novebo- 

 racensis by its striking skull characters. The latter species ranges down 

 the Alleghenies to northern Alabama, as evidenced by a typical specimen 

 which I collected on Lookout Mountain near Fort Payne, in July, 1911. 



