SKULL AND VERTEBRAE OF M. PENNANTL 65 



Skidl avid i^ertehrcv. 



Cranium. — The skull of this species is instantly distinguished 

 from that of M. martes by its obviously superior size. The larg- 

 est of six examples before me measures 4.40 in extreme length 

 by 2.40 in greatest zygomatic width. The under jaw is 3.00 in 

 length. There are other points. The zygomatic arch is nota- 

 bly lower. The skull is more contracted behind the orbits. 

 The lambdoidal (occipital) crest is stronger and more flaring ; 

 its termination as a broad flange back of the meatus audito- 

 rius is conspicuous when the skull is viewed from above, 

 whereas in the skull of M. martes, held in the same position, 

 the terminations of this crest are almost hidden by the bulge 

 of the brain-box. The bony palate is more narrowly and deeply 

 emarginate behind. The bullse auditoriie are relatively smaller 

 and flatter ; the meatus is absolutely smaller. Some other 

 minor points might be established. I observe no noteworthy 

 dental peculiarities, aside from superior size of the teeth. 

 This skull exceeds in length the large fossil one mentioned by 

 Prof. Baird from the Bone Cave of Pennsylvania, which is 

 little over 4 inches long. Several New York skulls are less 

 than 4 inches in length by little over 2 in greatest breadth. 

 One skull, of a very old animal, in which the sutures are all 

 obliterated, is remarkably massive, and broad for its length, 

 measuring only just 4 inches long by full 2.40 in breadth. 

 This series of skulls, like others in this group, shows that the 

 character of the sagittal crest, or elevation, is wholly transi- 

 tory ; in old specimens, the crest is a thin laminar ridge, while 

 in others there is a median longitudinal elevation half an inch 

 or more in width. The lambdoidal crest is subject to the same 

 modifications. The constriction of the skull back of the supra- 

 orbital processes also increases with age. 



Vertebrce :—G. 7, d. 14, 1. 6, s. 3, cd. 20 or 21 (Gerrard). Knee- 

 land [loc. su2)ra cit.) gives the caudals as 20; the rest of his 

 formula agrees with Gerrard's. Of the 14 ribs, he gives 10 as 

 apparently '' true " (sternal). 



The Pekan is much the largest of the genus, and indeed of 

 the whole Weasel kind (subfamily Mustelincv)^ excepting only 

 the Wolverene and Grison. In size, as in some other points of 

 form, vigor, and ferocity, it approaches the Wolverene, and is 

 obviously the connecting link between Miistela and Gido. It 

 has no immediate representative in the Old World. 

 5 M 



