VVILLISTON: RESTORATION OF PLATYGONUS. 



3^ 



posterior surface is nearly ilat transversely, the other two surfaces 

 nearly equal, gently convex, and meeting in a rnoderately sharp bor- 

 der. In the adult skull figured of the male the upper canines have 

 been largely worn away, the posterior border is nearly straight and 

 have an oval cross-section at the base with the anterior border 

 thick, the posterior thin. 



a b V «l e f P. refii.s- 



P. rom- 



8 8 



Length of first inferior molar 151210131311 



Width of same 10 9 911 1010 



Length of second interior molar 15 15 16 15 16 21 



Width of same ....". 11 10 13 12 11 15 



Length of third interior molar 20 21 23 21 21 28 



Width of same 12 11 12 12 11 16 



Length of first upper molar 14.. 11131312 17 



Width of same 13 •• 12 12 12 12 16 



Length of second upper molar 15161617 20 



Width of same 1414 14 15 18 



Length of third upper molar 19 20 . . 24 



Width of same ' ..1414.. 19 



Length of first inferior premolar 9 7 10 



Width of same 6 6 7 



Length of second lower premolar 10 10 10 



Width of same 7 8 



Length of third lower premolar loii 1012 



Width of same 910 910 



Length of first upper premolar 9 * 11 10 



Width of same 9 * 10 9 



Length of second upper premolar 10 10 10 11 



Width of same 12 11 12 10 



Length of third upper premolar 10 9 9 9 12 



Width of same 11 13 13 11 15 



T-ength of lower canine, crown 37 48 45 38 44 . . 



Antero-posterior diameter at base.. .. 10 15 14 11 12 



Width at base 71212 8 9 .. 



Length of upper canine 26 34 41 35 40 . . 



Antero-posterior diameter at base 12 17 19 12 14 .. 



Width same place 71010 9 9 



Of these measurements, those of a are taken from a young animal 

 in which the first molar is the only one of the permanent teeth 

 erupted. Those of d are from a skull in which the milk molars are 

 yet persistent. Those of r from the adult male skull which is figured; 

 </ from the oldest skull, as evidenced by the teeth, in the collection, 

 a female, which has the singular anomaly of but two upper premolars, 

 the first never having been developed, the first premolar of the lower 

 series being in consequence wholly unworn. The measurements of 

 e and /are from adult females skull; the skull of e is the one figured. 



S'Undereloped. 



