94 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. XIV. 



tion joins the lesser trochanter. A considerable depression lies between 

 its lower half and the base of the head of the femur. In many marsupials, 

 this ridge is only represented by a tubercle between the great trochanter 

 and the head. It is fairly well developed in Didelphis and in Perameles. 

 The lesser trochanter forms a prominent triangular projection on the 

 inner side of the femur separated from the head by a short rounded 

 notch. 



The distal end of the femur is of the usual character. The condyles 

 are produced backward to a marked degree and the intercondylar notch 

 is narrow and deep. The anterior rotular groove is broad and shallow 

 being scarcely more marked than in forms with a ligamentary patella. 

 The patella itself is rather short and broad and well ossified. This is an 

 important peculiarity of C&nolestes, for among living marsupials the 

 only others having an osseous patella are Tarsipes, Perameles and 

 Notoryctes. It is recorded also as present in the extinct genera Prothy- 

 lacynus and Amphiproviverra (Sinclair). 



The tibia is very long and much curved, resembling that of the 

 macropods and certain small saltatorial polyprotodonts, as Sminihopsis 

 and Antechinomys. Its proximal half is bowed inward and forward in a 

 long curve and is widely separate from the fibula but sweeps downward 

 into the same longitudinal axis for its distal half. The proximal half is 

 of the usual trihedral form, its wide inner surface being longitudinally 

 channelled and its antero internal surfaces convex. The distal half is 

 nearly cylindrical. The internal malleolus is highly developed, only 

 being equalled among forms examined in the macropods. Its perpendicu- 

 lar articular surface exceeds the horizontal surface of the end of the 

 tibia. 



The fibula is very slender, especially in its distal three-fourths. 

 Proximally it is compressed and somewhat expanded antero-posteriorly, 

 its inner surface being somewhat grooved. It is surmounted by a rather 

 large ovoid fabella. The tibia and fibula are closely appressed but not 

 fused in the distal half of their length. The hind leg of Ccenolestes is thus 

 of a cursorial or saltatorial type and closely resembles that of Antechi- 

 nomys, although even in this notably saltatorial form the internal 

 malleolus is relatively small. A leg of similar character with tibia and 

 fibula practically joined distally is found in Sminthopsis, Perameles, and 

 in the Macropodidae. In almost all other marsupials the tibia and 

 fibula are widely separate throughout. 



The relative length of the lower leg in C&nolestes is very great. In 

 proportion to the length of the femur, the length of the tibia in C&nolestes 

 is only exceeded, among forms examined, by that of the Giant Kangaroo. 

 The proportions in various genera are indicated by the following table, 



