86 



ON THE EXTINCT MAMMALIA OF 



Depth of zygoma just outside of the glenoid cavity, 

 Depth of lower jaw below the first tubercular molar, 

 Depth of jaw from end of coronoid process to angle, 27 

 Depth of jaw from condyle to level of angle, . Hi 



Breadth of base of coronoid process, . . 20 



Length of coronoid process to level with alveolar 



border, . . . . .18 



Breadth of condyle, . . . .12 



Antero-posterior diameter upper 



sectorial molar, 

 Transverse do. in front, 

 Antero-posterior diameter upper 



first tubercular molar, . 5 lines. 



Transverse do., . . 7 " 



Antero-posterior diameter upper 



second tubercular molar, . 3 " 3 

 Transverse do., , . 5 " 4 J 



Antero-posterior diameter upper 



third tubercular molar. 

 Transverse do., 

 Antero-posterior diameter lower sectorial 



molar, . . . . 6f 



Transverse diameter do., . ,3 



Antero-posterior diameter lower first tubercular molar, 4 A 

 Transverse " " " 3 



Antero-posterior diameter lower last " 2 J 



Transverse " " " 2 



6J lines. 



4 " 



5 " 



7 " 



Amp. vetus. 

 6 lines. 



12 " 



6 



7i 



3J 

 5i 



li 

 21 



7J 



C. latrans. 

 5 lines. 



8 " 

 22 " 

 lOi " 

 14 " 



13 

 10 



6i 

 8i 



OS 



5i 





9i " 



It 





C. occid's. 

 5 lines. 



9i " 

 261 " 

 Hi " 

 15 " 



16 

 10 



3i 

 6 



(I 



9i " 



4i " 



6i " 



Si " 





10 



a 



lOJ 



a 



3i 



(C 



31 



a 



41 



a 



41 



a 



3J 



a 



3J 



(C 



2i 



a 



2i 



a 



2 



11 



2i 



a 



Amphicyon gracilis. 



A small fragment of a lower jaw, containing two teeth, discovered by Dr. Hay den 

 in the calcareous marl rock of the Mauvaises Terres of White Eiver, apparently 

 indicates another species of Amphicyon much smaller than the preceding, for which 

 the name of A. gracilis is proposed. It was the only specimen appertaining to the 

 animal that has been found, and is represented in figure 7, plate I. 



The jaw fragment and teeth agree in their proportions with the corresponding 

 Tpaxis oi Ampliicyon vetus, in comparison with those of recent canine animals. The 

 portion of jaw is nearly as large as the corresponding portion in the Swift Fox, Canis 

 velox, while the teeth are not only much smaller than in this animal, but are smaller 



