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47 



RHINOCEROS 



rugose than some radii of A. fossigcr from Kansas. The articular proximal 

 portion, plate xiv. fig. 2, which is all that is preserved of the second radius, 

 indicates an animal generally larger than fossigcr, and, if one may use the 

 term, less pronounced in structure. It articulates perfectly with the distal end 

 of the right humerus shown in plate xvi. fig. 7, and may have belonged to the 

 same animal. 



Carpus. — The scaphoid, plate xiii. fig. 8, is more massive and its radial 

 articular face more triangular in outline than the corresponding bone in an 

 immature specimen of R. unicornis. The unciform, which has its posterior 

 projection broken off, is slightly smaller, but a little more heavily built than in 

 the same specimen of unicornis, and it, as well as the fourth metacarpal, exhibits 

 articulations for the rudimentary fifth metacarpal. 



Metacarpals. — The second metacarpal is decidedly lighter than that of 

 unicornis, while the fourth metacarpal is practically of the same size in the 

 two animals. Plate xiii. figs. 6 and 7. 



Femur. — Only the distal portion of a femur, plate xvi. fig. 8, is present, 

 and this has a portion chipped off the outer condyle. It is distinguishable 

 from the distal end of the femur of A. fossigcr only by its superior size, while 

 in turn it is smaller than the corresponding portion of the femur of Indian 

 rhinoceros. It agrees in size with part of a femur of A. nialacorhinus in the 

 possession of Professor Cope. 



Tibia. — -The distal end of the tibia, plate xvi. fig. 5, is wide and trans- 

 versely flattened, the inner face is also flattened, while the outer is very sharp, 

 the general character of the bone being square and angular. The transverse 

 diameter is much greater than the antero-posterior diameter, which is not the 

 case in the tibia o{ fossigcr, while the tibia of malacorhiniis was also much 

 longer than that of the other species. 



Rather curiously in the present specimen, the distal end of the fibula is 

 ankylosed with the tibia, which, as previously noted, often occurs in Western 

 specimens oi fossigcr, but has not yet been found in the Florida representatives 

 of that species. 



The astragalus, plate xvi. fig. 6, is slightly wider than high, with the tibial 

 groove deeply cut and the cubo-navicular articulation rather narrow fore and 

 aft, contrasting in these points with A. fossigcr and resembling R. unicornis. 



The calcaneum, plate xi. figs. 3 and 4, is remarkable for its shortness 

 and depth, again differing from fossigcr and agreeing with R. unicornis. It is 

 interesting to note that the long metatarsals of nialacorhinus are associated 



