146 



ON THE EXTINCT MAMMALIA OF 



a 

 <c 



Distance from auditory meatus to fore part of first premolar, 

 Distance from auditory meatus to ant-orbital margin, 

 Breadth outside auditory bullae, 

 Breadth at auditory meatus, 



" malar bones midway below orbits, 



infra-orbital foramina, . 

 above first premolar, 

 above middle true molar, 

 Height of orbit from base of lower jaw. 

 Breadth of orbit. 

 Height of lower jaw at condyle, 



middle true molar, 

 second premolar, 

 angular apophysis, 

 Length of upper molar series exclusive of the isolated premolar. 

 Length of lower " " " " 





Diameter of first upper premolar, 

 second " " 

 third " " 

 temporary true molar, 

 first permanent upper true molar, 

 second " " " 



third " " " 



second lower premolar, 

 third " " 



temporary true molar, 

 first permanent lower true molar, 

 second " " " 



third " " " 



u 

 ee 

 a 

 ee 

 ee 

 ee 

 ee 

 ee 

 ee 

 ee 

 ee 

 ee 



antero-posterior, 

 ee 



ei 

 le 



ee 

 ee 

 ee 



Lines. 



^ 1 

 Of ; 



4i 

 41 

 4 J 

 5i 



7 



■4i 



41 



6 



5 



6J 



Lines. 



57 



28 



25 



21 



28 



14 

 7i 



22 



20 



14 



23 

 7 

 7 



10 



30 



32 



transverse, 



te 



ee 



ee 

 li 

 ei 

 ee 



le 

 ee 

 ee 



1 



O 



O 



3i 

 5 



5i 



6 

 1 



n 



2i 

 3h 

 31 

 3i 



In Dr. Hayden's expedition to the Mauvaises Terres of White River, in 1866, he 

 obtained a number of small fragments of jaws with molar teeth oi Pcebrotherium 

 Wllsoni. One of the specimens consists of a fragment of the upper jaw of an adult 

 individual, containing the back two premolars on both sides, portions of the second 

 one, and on the left side portions of the succeeding two true molars. 



The back two premolars are represented in figure 7, plate XII. They are of rather 

 less width than the teeth they replace, as compared with those contained in the skull 

 above described. 



