154 



DINOCERATA. 



This si^rface (Plate XLIX, figure 1) is moderately roughenerl, 

 especially at the edges, for attachments of ligaments. The outer, or 

 fibular, side, shown best in figure 4, is short along the line of the foot, being 

 encroached upon by the articular face for the calcaneum on the proximal 

 end, and one for the fifth metatarsal on the distal end. 



The plantar aspect of the bone (figure 3 ) presents a single, or bifid, 

 tubercle, and, on the inner face (figure 2), is an elongate articular surface 

 fill- union with the navicular. This surface is confluent with the face for 

 articulation with tlie astragalus, and thus serves to distinguish the proximal 

 from the distal end of the bone, which often closely resemble each other. 



The proximal surface (figure 5) is covered ])y two articular facets. 

 The inner one, large and sub-triangular, concave In both directions, and 

 nearl}' perpendicular to the axis of the Ijone, moved, during life, upon the 

 outer distal face of the astragalus. This face is, in the specimen figui-ed 

 on the Plate, widely confluent Avith a smalkn- oval face for the calcaneum. 

 In figure 14G, below, the face for the calcaneum (c) is much less widely 

 confluent with that for the astragalus, being nearly separated from it. 

 In both specimens, the calcaneal fixce is slightly convex transversely, and 

 somewhat inclined to the axis of the bone. 



Figure 145. — Right dilioid of nhwceras mirdhik, Marsli (No. 1528); side view 

 FlCHRE 146. — The same bone ; proximal end. 



a. face for astragalus; c. face for calcaneum ; rat IV. face for fourth metacarpal ; n. face for navicular. 

 Both figures are one-half natural size. 



Tlie cuboid bone In one hidividual of Dinoceras is represented in the 

 two cuts above. 



The distal face (Plate XLIX, figure (J) also presents two articular 

 surfaces, for the support of the fourth and fifth metatarsal bones. The 



