104 MEMOIRS OF THE CARNEGIE MUSEUM 



Greatest length of lower jaw 116 mm 



Depth of lower jaw below M.j 19 " 



£1 (1 11 II p_ 1Q " 



Height of coronoid process 56 



Length of sup. premolar- molar series 58 



" series 43 



" sectorial 15 



Breadth " " 9.5 " 



" " M.i 15.5 " 



li a n 2 ^ ^ 11" 



Antero-posterior diameter of sup. canine at base of crown 8.5 " 



Transverse " " ' " " 6 



Length of inferior premolar-molar series 65 " 



" " series 38 " 



" " sectorial 16 " 



" Pi 11- " 



Breadth " " 5.5 " 



Antero-posterior diameter of lower canine 9 '' 



Transverse " " " '. , 5 " 



Expanse of condylar cotyloids of atlas 32 " 



Length of centrum of axis including odontoid process 44 '' 



Relations of Protemnocyon In flatus. 



From the foregoing description and the accompanying figures it will readily ap- 

 pear that the tj^pe of the present genus and species very closely resembles Cope's 

 Daphoenus hadshornianus and there is no doubt that the two are generically identical, 

 though the species are easily distinguishable by the structure of the second inferior 

 molar and of P.-^. From several characters already pointed out in the description of 

 both the present and the preceding genus it has appeared to the writer best to sub- 

 divide Daphoenus into two genera, viz., Daphoenus and Protemnocyon, including in 

 the latter Cope's species, described as D. hartshornianus, which would then be known 

 as Protemnocyon hartshornianus. 



The present genus appears to stand directly ancestral to Temriocyon coryphseus Cope 

 of the John Day. The relationships between the two are shown not only in the den- 

 tition, but by certain characters exhibited by the skull and mandible as well. Among 

 the latter maybe mentioned the capacious brain-case, reduced sagittal crest, broad fron- 

 tals, slender and straight mandible. T. coryphaeus has advanced so far beyond P. injiatus 

 as to have completely ossified t^^mpanics, which appear as large inflated auditory 

 bullae. The molars are also much more reduced in the John Day form, the second 

 tubercular having become much smaller than in Protemnocyon of the White River, 

 while the third has disappeared entirely, as might be expected from the exceedingly 

 reduced nature of that tooth in P. hartshornianus and injiatus, the earlier forms. 



