234 VERTEBRATE REMAINS, PORT KENNEDY BONE DEPOSIT. 



No 2 (with angle of mandible). 



mm. 

 Length of m T ; 11 



Length from m T to condyle ; 26 



" " " to angle; 23.5 



Depth of ramus at m T ; 7.5 



No. 3 (with canine). 



Length of dental series ; 31 



" of true molars and pm. 1 ; 21 



" of m T ; 11.5 



Depth of ramus at m T ; 8 



This species represents a section of the genus distinct from M. mephitica, with 

 which it is connected by M. orthostichus. 



Mephitis orthostichus Cope (PI. XVIII, figs. 8, 8a). Proc. Acad. Nat. Sci. Phil., 1896, p. 389. [Type No. 

 71, Mus. Acad. Nat. Sci. Phil.] 



This species is represented by superior first molars of seven individuals and 

 mandibular rami of three others. Unfortunately, in no case are inferior and superior 

 dentition of the same individual preserved together. In one individual both rami 

 are preserved. 



This species is intermediate in size between M. mephitica and M. putorius, and 

 resembles the latter species in the small metaconid. It resembles the M. mephitica 

 in the rising inferior outline of the mandibular ramus, and differs widely from both 

 species in the character of the superior mi. 



The superior ra 1 instead of presenting two parallel longitudinal crests, has a 

 slightly curved crest representing the paraconule, which reaches a trihedral cusp, 

 the metaconule. Thus is produced an internal longitudinal crest which presents a 

 convexity anteriorly and an angle posteriorly, and an entrant angle between the 

 two. The protocone is a mere cingulum which rises to the apex of the metaconule, 

 and extends no further, so that there is no posterior ledge, as in the existing species. 

 While the internal crest is quite different in its zigzag character from that of 

 M. fossidens, the species further differs from the latter in the premolars, which do 

 not overlap, and in the inferior size. The posterior border of the m 1 is not so 

 deeply notched as in M. fossidens. 



The inferior dentition does not differ from that of M. mephitica, except in the 

 small metaconid and entoconid, and the flatter posterior-internal face of the pm. 1, 

 in which it resembles M. fossidens. The third premolar is in contact with the 

 canine, and has two roots which do not overlap those of the second. The crown is 

 longer than wide, and has a heel with a recurved rim. The third has the same, 

 while the fourth is a narrow heel, with a recurved rim all round it. In no speci- 

 men is the angle of the mandible preserved. 



