748 



MAMMALIAN ANATOMY 



of the dorsal surface of the bone, where it is concave. It is less 

 convex from side to side, except at the distal end, which is concave. 

 Its proximal margin is rounded ; the tibial margin is emarginate and 

 separated from the other facet by a rough groove for the interosseous 

 ligament from the astragalus. The distal margin is slightly arcuate, 

 and the fibular margin is emarginate above and arcuate below. The 

 surface faces at first dorsally, to the tibial side and slightly proxi- 

 mally ; then dorsally, to the tibial side, and distally ; it articulates with 

 a surface on the fibular side of the plantar surface of the astragalus. 



FIG. 565. 



Groove for TENDO ACHILLIS. 



Internal Tuberosity. 



Posterior Part of Internal Surface. 



Groove for INTEROSSEOUS LIGAMENT. 



Lesser Process. 

 With Astragalus. 



With Neck of Astragalus- 



With Head of Astragalus. 



With Scaphoid. 



With Cuboid. 



External Tuberosity. 



- Posterior Part of External Surface. 



With Astragalus. 



Pit for Annular Ligament of 



EXTENSOR LONGUS DIGITORUM. 



Peroneal Tubercle. 



LEFT CALCANEUM, DORSAL SURFACE. 



The other facet lies mainly on the tibial side, on the dorsal surface 

 of the lesser process, and is continued distally along the tibial border 

 of the dorsal surface proper. The part on the lesser process is almost 

 circular, and slightly concave ; it faces dorsally and proximally ; a 

 small proximal area, however, is not on the same plane as the rest, 

 but faces dorsally and to the proximal and tibial sides. The fibular 

 side of the facet is continued forward on the tibial margin as a narrow 

 line, which widens and ends at the tibio-distal angle in a uniform 

 concavo-convex surface which faces to the dorsal and proximal sides. 

 The facet and its prolongation forward articulate with a corresponding 

 elongated facet on the tibial side of the plantar surface of the body, 

 neck, and head of the astragalus. 



The remaining distal part of the dorsal surface of the calcaneum 

 is four-sided. The proximal margin is continuous with the facets and 



