352 



NOTES ON THE CANIDiE OF THE WHITE EIVER OLIGOCENE. 



distal fibular facet is quite large, being much as in Dinictis. and consequently much 

 larger than in the recent Ca niche. 



The fibula (PI. XX, Figs. 19, 20), which is greatly reduced in the modern dogs, is 

 in Daphcenus much stouter and has heavier ends, both proximal and distal. In Canis 

 these ends have the appearance of being reduced and simplified from the condition seen 

 in the White River genus. In the latter the proximal end of the fibula is relatively very 

 large, especially in the fore-and-aft dimension, in which it considerably exceeds that of 

 Dinictis, though the excess is principally due to a large tuberosity which projects from 

 the hinder border, and which is present, though much less prominent, in the Machairo- 

 dont. The facet for the head of the tibia is longer antero-posteriorly and narrower 

 transversely than in the latter, forming a long, narrow, irregular oval. The shaft of the 

 fibula is slender, though very much thicker both actually and proportionately than in 

 Canis, and has about the same proportions as in Dinictis ; it is laterally compressed, the 

 principal diameter being the antero-posterior one, and of oval section, though its size and 

 shape vary from point to point in an irregular fashion. 



The distal end of the fibula resembles that of Dinictis, though it is somewhat smaller, 

 in proportion to the length of the bone. The enlargement is both antero-posterior and 

 transverse and gives rise to a very stout outer malleolus, at the postero-external angle of 

 which is a deep sulcus for the peroneal tendons. The distal tibial facet is rather larger 

 than that of Dinictis, while the surface for the astragalus is somewhat smaller, the two 

 together making a high narrow band. 



Measun menU. 



Femur, length (fr. head) 



breadth of proximal end 



" distal end 



" rotular groove 



Tibia, length 



breadth of proximal end 



" " distal end 



Fibula, ant-post, diameter piox. end 

 " " " dist. 



No. 11421. 



No. 11424. 





.14!! 





.031 



.021 



.021 



.0145 





No. 11423. 



0.195 

 .044 

 .038 

 .014 



.036 

 .025 

 .019 



.017 



VII. The Pes (PI. XX. Figs. 21, 21«, 22). 



The pes, which displays structures of the highest interest, is much better represented 

 in the collection than the maims and may be more adequately described. As a pre- 



