MUSEUM OF COMPARATIVE ZOOLOGY, 



79 



The tibia has a large trihedral head, with large external and small internal 

 surfaces for the femoral condyles, and prominent bifid spine. The cneiuial crest 

 is very well developed, and just posterior to it on the external side is a very 

 deep tendinal sulcus. The shaft is quite long and stout, with oval section and 

 broad distal end. The surfaces for the astragalus are deeply incised, and the 

 external one is somewhat the larger. The tongue is broad and thick, corre- 

 sponding to the breadth of the groove in the astragalus. The internal malle- 

 olus is very long, and forms a tongue-like projection from the antero-iuternal 

 corner. 



Thejihila is as completely reduced as in any ruminant. The proximal end 

 is ankylosed with the tibia, where it forms a short sharp process. The distal 

 end is not represented in any of the specimens, but from the structure of the 

 tibia it is plain that it was a small nodule wedged in between the distal end of 

 the tibia and the fibular process on the calcaneum. Between the two distal 

 fibular facets of the tibia is a groove for the reception of the rudimentary shaft. 



The carpus is like that of recent deer : the bones of the proximal row are 

 high and narrow, those of the distal row low and broad. The scaphoid is deep 

 antero-posteriorly, and broader in front than behind, 

 where it is much narrowed by the great lateral exten- 

 sion of the lunar; the proximal surface is directed 

 very obliquely backwards and inwards, and is deeply 

 incised so as to form a very firm interlocking joint 

 with the radius ; this facet is divided into a strongly 

 convex anterior portion, and an as strongly concave 

 posterior portion. The lunar is curiously shaped ; it 

 is broadest in front and behind, and contracted in the 

 middle ; the anterior surface is transverse, the poste- 

 rior very oblique. The radial surface is directed ob- 

 liquely inwards parallel to that of the scaphoid. The 

 distal surface is divided nearly equally between the 

 magnum and the unciform, which meet at a very open 

 angle, and the " beak " is barely indicated. The inner face of the lunar is 

 nearly vertical, the outer very oljlique, as the upper part of the bone is consid- 

 erably wider than the lower, corresponding to the*- reduction in width of the 

 proximal portion of the cuneiform. The latter bone has a broad distal surface 

 and small saddle-shaped facet for the ulna, which is prolonged well down upon 

 the postero-extemal surface. The cuneiform rises above the level of the lunar, 

 and presents a small oblique surface, which articulates with the radius. The 

 pisiform fiicet is high and very narrow. The trapezium is not preserved in any 

 of the specimens, but its presence is demonstrated by a small facet on the pos- 

 tero-internal angle of the trapezoid. It was obviously very small and did not 

 reach the scaphoid. The trapezoid and magnum have coalesced ; the proximal 

 surface of the compound bone is mostly occupied by the scaphoid, the facet for 

 which is low and concave in front, rising behind to a low broad convexity; the 

 distal surface is nearly flat. Tbe unciform is narrower and higher than the 



~r? 



Figure 7. — Carpus of 

 Blastonuri/x, iiat. size, 

 posterior view. 



