NOTES ON THE CANIDiE OF THE WHITE EIVER OLIGOCENE. -)-A 



The femoral condyles are feline rather than canine in shape ; they are small and of 

 nearly equal size, though the outer one is slightly the larger of the two, and jiroject 

 much less strongly behind the plane of the shaft than in Cards. They are also less 

 widely separated and less expanded transversely than in the latter genus. As in so 

 many features of the limb bones, the whole distal end of the femur is more like that of 

 Dinictis than it is like the corresponding part of the modern dogs or cats. In Dinictis, 

 however, the rotular groove is shorter proximo-distally and broader, and the condyles are 

 even less prominent. 



The patella is very different from that of the recent Canidce, in which group this 

 bone is small, narrow and thick, but has more resemblance to that of Dinictis. It is 

 quite broad, but very thin in the antero-posterior dimension ; the anterior face is more 

 roughened than in the Machairodont genus and the proximal end is more pointed, not so 

 abruptly truncated. The facet for the rotular trochlea of the femur is, in correspondence 

 with the shallowness of that groove, but slightly convex transversely and slightly concave 

 proximo-distally. 



The tibia (PL XX, Figs. 19, 20) is relatively short and slender, and bears consider- 

 able resemblance to that of Dinictis, more than to that of Canis. The proximal facets 

 for the femoral condyles are small and but little concave ; the outer facet is somewhat 

 larger than the inner, and projects farther beyond the line of the shaft, both posteriorly 

 and laterally. On the distal side of the overhanging shelf thus formed is a facet for the 

 head of the fibula, which is much larger than in the recent dogs and more rounded in shape 

 than in Dinictis. The spine of the tibia is very low and is more distinctly bifid than in 

 the Machairodont genus, though much less so than in Canis. As in the former, the 

 cnemial crest is not very strongly developed ; it is far less prominent than in the existing 

 Caniclw and does not descend so far upon the shaft as in them. 



The tibial shaft is slender and nearly straight, not displaying the lateral and antero- 

 posterior curvatures seen in Canis ; proximally the shaft is of trihedral section, becoming 

 approximately cylindrical below and transversely oval at the distal end. The latter is 

 shaped much as in Dinictis and is conspicuously different from that of Canis; the 

 astragalar facets are less deeply incised, and the intercondylar ridge is less elevated than 

 in the latter, but the facets are deeper and the ridge higher than in the Machairodont, in 

 correlation with the deeper grooving of the astragalus. The large transverse sulcus, 

 which in the recent dogs invades these astragalar facets, is not shown in Daphcetvus. 

 The internal malleolus is very large and resembles that of Dinictis, save that its posterior 

 border is more inclined and the process is thus distally somewhat narrower. The sulcus 

 for the posterior tibial tendon is very distinctly marked, more so than in Canis. The 



a. p. s. — vol. xix. 2 s. 



