162 DINOCERATA. 



roughened at both the proximal and distal ends, but medially it is 

 smoother and constricted, especially below, where a large, and prominent, 

 tubercle occupies the proximal portion of the under sui'face of the bone. 

 This tubercle is shown in figure 9, and also, in profile, in fig>ures 8 and 

 10, where it is seen to project considerably beyond the j^roximal articular 

 face. 



The proximal end of the bone (figure 11) is oblique to its axis, and 

 presents two distinct articular faces ; the larger on the inner, or tibial, 

 side of the bone, for the mesocuneiform, and the outer, on the fibular side, 

 for tlie eetocuneiform. The latter face is also confluent with a lateral 

 facet, where the bone, during life, touched the third metatarsal. This 

 face is well shown in figure 10. 



The distal end (figure 12) is large, rounded, and somewhat oblique 

 to the axis of the bone. The articulation for the phalanx is flattened, but 

 may be slightly convex, or, in a transverse direction, more or less concave. 

 Two well developed sesamoids moved in broad sliallow grooves below, 

 the faces for these bones, taken together, being about as large as that for 

 the phalanx. 



The Third Metatarsal. 

 (Plate LI, figures 13-15, Plate LII, figures 1-3, and Plate LIV, figure 2.) 



The third metatarsal is of about the same length as the second and 

 the fourth, and is a little less robust than the second. 



It lias a distinct shaft, which is smooth and constricted niediall}', but 

 more or less roughened and tubercular toward the extremities, especially 

 near the distal end. 



The ])rt)ximal face of the bone (Plate LII, figure 2) is somewhat 

 oblique tt) its axis, and presents a sub-triangular articular face for the 

 outer facet of the eetocuneiform. This facet is confluent, along its inner 

 margin, with a small lateral face for union with the second metatarsal, as 

 shown in Plate LT, figure 14. Ojiposite this, tliere is also an oval face 

 (Plate LII, figure 1) supported on a flattened tubercle, and meeting, 

 during life, a similar face on the fourth metatarsal. 



