80 Douglass — New Species of Meryeochcerus in Montana. 



All of the teeth were closely crowded. The incisors were 

 laterally compressed. The canine is nearly circular in section. 

 Pm 1 is quite large but not high. There is an anterior inner 

 angle and a posterior outer one, Between these the tooth is 

 broadly convex, being nearly semicircular in front, and less 

 prominently convex behind. Pm 2 is more nearly transverse 

 than in a line with the dental series. While its longitudinal 

 diameter is l'6 crn , it occupies only one-half that amount of 

 space on the alveolar border. Pm 3 is also inserted diagonally 

 but not so much so nspm 2. In pm 1± the posterior part is pro- 

 portionally broader than in M. proprius. The fold of enamel 

 which separated the posterior lobes has by wear become an enamel 

 lake. It occupied the same position as in M. laticeps. Pm 2 

 has much the form of the corresponding tooth in M. proprius 

 except that the anterior lobe has been twisted inward and back- 

 ward. The same is true of pm 3, but on the posterior inner 

 side a little rounded lobe has been added. This is true also of 

 pm 1± but the lobe is larger. 



Measurements. 



of ramus to second lobe of m 3 _ _ 



of three lower incisors 



of premolars and first two molars 



of premolar series - _ 



of ms 1 and 2 and anterior lobe of m 3 

 of canine, about 



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From Loup Fork beds, on east side of Lower Madison 

 Yalley. Found by Earl Douglass. 



of canine 



of pm 1 



of pm 1 _. 



of pm 1 _ 



of pm 2 



of pm2 



of pm 2, crown only 



of pm 3 



of pm 3_ 



of pm 3 _.. 



of pm 4 



of pm 4 . 



of pm 4 



ofm 1 



ofm 1 _ 



of m 1, crown on outside _. 



ofm 2 



ofm 2 



of m2 



of m 3, middle lobe, about. 



M. 

 128 

 010 

 092 

 05 L 

 055 

 009 

 009 

 012 

 014 

 023 

 016 

 008 

 0125 

 017 

 011 

 011 

 019 

 014 

 012 

 018 

 0155 

 0054 

 024 

 0187 

 015 

 020 



