THE HIND FEET. 117 



In the specinieu there ligured, the lace for the oaleaneum may be 

 briefly described as in the form of a horse-slioe witii tiie hiteral branches 

 so broad as to leave only a narrow interval between them. 



Tlie lateral portions, or branches, present two oval, concave faces, 

 and they are united behind by a broad band, running around the 

 posterior end of a deep, narrow groove, dividing the anterior parts of the 

 articulation, and leading backward to a foramen tlirough the bone. In 

 the speciniLni figured, this foramen is small and obli([ue, and no opening- 

 is seen through the bone. Along the outer, or fibular, margin of the 

 bone, the articular face is confluent for a short distance with that for the 

 fibula on the side of the astragalus. Near the center of the inferior surface, 

 the inner ramus of the calcaneal articular facet is confluent at the end with 

 tlie face for the cuboid. 



Anotlier, and more couunon, form of articulation with the calcaneum 

 is shown in figure 140, below, wliere the lower surface of the astragalus 

 presents two distinct faces for tlie cahtaneum. The outer of these is broad 

 and rounded, nearly flat transversely, concave from before backward, and 

 separated by a deep groove from the inner, more elongated surface. This 

 groove leads backward into a large foramen, passing through the posterior 

 part of the bone. The inner portion of tbe calcaneal face is longer than 

 the outer, and more concave from betVtre backward. From side to side, it 

 is nearly flat, and, in front, it is more or less confluent witli the face for the 

 cuboid, and often also with that for the uaviculai-. In a few specimens, 

 the usual foramen near the liiuder border of the bone is represented by a 

 notch only, as in figures 141 and 142, below. 



The anterior part of the under surface of tlie astragalus presents two 

 flattened, moderately convex, and verv une(pial, articular taces. The 

 larger one of these is for articidation with the navicular, and the smaller, 

 for the cuboid bone. 



Tlie presence of a face for the cuboid is in strong contrast with the 

 structure of the foot of tlie elephant, in which the cuboid is supported by 

 the calcaneum, and the navicular wliicli covers the whole anterior face of 

 the astragalus, not allowing the cuboid to come in contact with that bone. 

 In the D'u/.ocerafa, this specialization does not oci-ur. 



