388 PROCEEDINGS OF THE ACADEMY OF [1896, 



The inferior molars resemble those of M. mephitica but differ 

 in the following points : The metaconid is much smaller, resem- 

 bling that of M. putoy-ius. The entocouid is small and low. The 

 Pm. 1 has a flat face, presenting backward and inward and is 

 bounded by a ridge on the external side. This face is rounded in 

 M. mephitica. The overlapping of the Pm. 2 and 3 does not oc- 

 cur in the latter. The inferior border of the ramus rises gently 

 from below the posterior part of the M. y. The angle is prominent 

 and the condyle occupies a position inferior to that seen in Mephitis 

 mephitica and M. putorius, in the two jaws in which this part is pre- 

 served. It does not rise above the level of the molars as it does in 

 M. mepjhitica. 



The M. i is the most characteristic part of the dentition. The 

 crown is traversed by two parallel anteroposterior crests ; the ex- 

 ternal consisting of the paracone and metacone, and the internal of 

 the paraconule and metaconule. The posterior border is deeply 

 notched between the two, and the anterior border less so. The pro- 

 tocone is represented by a cingulum which occupies the anterior 

 half of the interior base of the crown, enclosing a fossa with the 

 paraconule. Its border then rises vertically to the inner longitu- 

 dinal crest which it joins about the middle. Just exterior to this 

 crest is a small tubercle which may represent a metaconule. An 

 external cingulum except at the base of the metacone. No ante- 

 rior or posterior cingula. 



In the existing species of Mephitis the protocone is continued 

 into a wide ledge round the posterior side of the crown as far as the 

 base of the metacone. The paraconule is V-shaped and does not 

 reach the posterior part of the crown. 



Measurements. m. m. 



Diameters of M. 1 j anteroposterior (greatest) ; 8 



( transverse ; y.o 



Length of inferior sectorial ; 11 



Depth of mandibular ramus at ^ ; 6 



No. 2 (with angle of mandible). 



Length of M.y; 11 



Length from M. y to condyle ; 26 



Length from M. 7 to angle ; 23.5 



Depth of ramus at M, y ; 7,5 



