24 



MAMMALIA 



CLASS V 



with high coronoid process and low articular condyle extending beyond the 

 angle of the jaw. Anterior upper / directed yertically downward, and lower 

 first / directed obliquely upward and forward. Upper P with biserially arranged 



rows of tubercles, and 

 lower P increasing in size 

 in a posterior direction, 

 trenchant, lamellar, and 

 with channelled lateral sur- 

 faces. Upper and lower M 

 each with, two rows of 

 tubercles. Purbeck and 

 Wealden ; England. 



Allodm Marsh. Upper 



a 6x3 



Fig. 30. 



Bolodan crassidens Owen. Purbeck beds of Dorsetshire. A, 

 Fragment of upper jaw, i/j. B, The same, ^/i (after Osborn). live, 

 maxilla ; pinx, premaxilla ; s, suture between maxilla and pre- 

 maxilla ; Ji, infraorbital foramen; i, incisors; pm, premolars; 

 m, molars. 



Fig. 31. 



AUacodon pumilus Marsh. Upper 

 Cretaceous of Wyoming, a, the tliree 

 premolars of the upper jaw, i/j ; 6, the 

 same, %. (After Marsh.) 



jaw similar to that of Plagiaulax, but Avith three /. Upper Jura ; Wyoming. 



AUacodon Marsh (Fig. 31). Upper Cretaceous; North America. 



Ctenacodon Marsh (Fig. 32). Lower P slightly channelled on the upper 

 surface. Upper M with only two large 

 tubercles on the outer face. Upper 

 Jura; Wyoming. 



Neoplagiaulax Lemoine (Liotomus 



Ctewicodon poteiis Mareli. Upp«r Jurassic of Wyo- 

 ming. Lower aspect of right upper jaw, ■*,! (after 

 Marsh), a', tirst premolar, and b, fourth premolar ; 

 VI, maxillary base of zj-gomatic arch. 

 a h 



Fig. 34. 



Cimolomys (Cimolodon) nitidxis Marsh. Upper Cret- 

 aceous of Wyoming. (After Marsh.) o, Xext to the 

 last molar of the lower jaw, i/i ; ^i the same enlarged. 



Fig. 33. 



Ptilodus (/rociZis Gidley. Lowest Eocene of Fort 

 Union beds, Montana. A, Skull and lower jaw. B, 

 Upper jaw. C, Lower jaw. 2/^. (After Gidley.) 



Cope). Lower jaw with only one large grooved P and two JIF. 

 Eocene of Rbeims, France, and New Me.xico, U.S.A. 



Low 



r'er 



