NOTES ON THE CANID^E OF THE WHITE RIVER OLIGOCENE. 39] 



shallower notch, while the digital fossa is relatively much smaller. The second tro- 

 chanter occupies nearly the same position as in the modern genus, though somewhat more 

 posterior, so that it is almost or entirely concealed when the femur is viewed from the 

 front ; it is of about the same prominence as in the existing dogs, but rather more slender 

 and pointed. The intertrochanteric ridge, which connects the greater and the second 

 trochanters, is rather better developed than in Cants, especially in the larger and longer- 

 limbed individuals. What may fairly be regarded as a remnant of the third trochanter 

 is present in the form of a low, short, thickened and rugose ridge, which is placed a short 

 distance below the great trochanter. The third trochanter is all but universal among 

 the Creodonta, and in rudimentary form it })ersists in many of the earlier and more 

 primitive carnivores, such as Dinictis, but it is somewhat surprising to find it retained in 

 so advanced a genus as Cynodictis. It is true that in certain muscular and powerful 

 domestic breeds of dogs the third trochanter recurs, though it is not distinctly shown in 

 the existing wild species of Canidce. 



The shaft of the femur is long, slender, arched strongly forward and slightly toward 

 the internal or medial side. As would naturally be expected in so small an animal, the 

 ridges for muscular attachment are not so prominent as in the modern species. On the 

 anterior face no ridge for the vastus externus muscle is distinguishable and ou the poste- 

 rior face the linea asj)era is neither so long nor so prominent as in Cards. The distal end 

 of the femur has quite a different appearance from that seen in the existing members of 

 the family ; a difference which is principally due to the smaller size and less prominent 

 projection of the condyles and rotular trochlea. The trochlea resembles that of the 

 viverrines in being shallow and in having the two borders of nearly equal height and 

 length, and also in the absence of any distinctly marked suprapatellar fossa. On the 

 other hand, this trochlea is relatively narrower and extends farther up the shaft than in 

 the civets. The condyles are small, of nearly equal size and prominence, and are sepa- 

 rated by an intercondylar space which is relatively narrower than in Can is ; small sesa- 

 moid bones were evidently, as in the existing species, attached to the proximal faces of 

 the condyles. 



The patella is viverrine, or more accurately herpestine, rather than canine in char- 

 acter. It is a short, rather wide, thin and scale-like bone, of subquadrate more than 

 ovate shape. The articular surface for the femur, in correlation with the shallowness of 

 the rotular groove, is but slightly concave proximo-distally, and even less convex trans- 

 versely. 



The tibia, as in Canis, is of about the same length as the femur. Compared with 

 the radius, the tibia seems to be very long, but that this is due rather to the shortness of 

 the radius than to the elongation of the tibia, appears from a comparison with the verte- 



A. P. S. VOL. XIX. 2 X. 



