90 MEMOIRS OF THE CARISTEGIE MUSEUM 



articulation for the fibula is small. Internally the distal end of the tibia is produced 

 into a broad internal malleolus. The grooves for the flexor tendons are fairly Avell 

 defined. The ridge separating the external and internal articular surfaces for the 

 astragalus is low as in the cats and the external surface is transversely broader than 

 the internal, though the latter is more extended antero-posteriorly. 



The Fibula. — PL XIX., Figs. 5 and 6. This bone is cat-like in almost all its char- 

 acters. The shaft is very slender and much flattened transversely. The proximal 

 end is much expanded, with a deep external concavity embraced between prominent 

 anterior and posterior rugose tuberosities, while on the internal side there is a sharp 

 median ridge extending for an inch below the ovate articular surface for the tibia. 

 For a short distance below the termination of this ridge the shaft becomes a slender, 

 cylindrical rod of bone, circular in cross-section, a little below this its antero-pos- 

 terior diameter increases and it becomes a flattened bar with the external surface 

 gently convex. Distally the fibula is expanded in both directions. On the postero- 

 inferior angle there is:an external malleolus, while just below and a little anterior to 

 this is a prominent tuberosity, as seen in some of the cats, though absent in others 

 and in the dogs generally. A deep groove for the peroneus longus is thus formed 

 between this tuberosity and the external malleolus. The articular surface for. the 

 tibia is small, that for the astragalus is much larger. On comparing this bone with 

 the fibula of Hoplophoneus, a contemporaneous sabre-toothed cat, I note that it re- 

 sembles more closely that of the modern felines. While the fibula of Hoplopho- 

 neus is distinctly feline, yet it bears a certain resemblance to that bone in the 

 creodonts not shown by" the fibula in Daphcenus. These resemblances are to be 

 seen in the shorter and more cylindrical shaft and in the rather less expanded 

 extremities. 



The Tarsus. — PI. XVIII., Fig. 9. The tarsus of Daphcenus and indeed the en- 

 tire pes is decidedly feline rather than canine in structure, and moreover it more 

 closely resembles the pes in modern cats than does the pes of Hoplophoneus. All 

 the elements usually found in the tarsus of the carnivora are present. 



The calcaneum is comparatively rather short and stout. The tuberosity is more 

 expanded antero-posteriorly than in the modern cats or Hoplophoneus. On its an- 

 terior surface midway between the summit and the articular surface for the astraga- 

 lus there is a prominent rugosity. At the apex the internal tuberosity is more ele- 

 vated than the external and they are separated by a shallow median groove for the 

 tendon of Achilles. Compared with modern dogs or cats the inferior portion of the 

 calcaneum is remarkably short and broad. The external articular surface for the 

 astragalus is flat transversely, but very convex supero-inferiorly. It is continued 



