MUSEUM OF COMPARATIVE ZOOLOGY. 95 



The Skeleton. 

 (Plate III.) 



Vertebra?. — The atlas resembles that of E. unicornis, with extremely broad 

 transverse processes. A well preserved axis has a low tuberosity representing 

 the spine ; there is some doubt whether this is the normal adult condition, al- 

 though the absence of the spine would accord with the low occiput and hornless 

 nasals. The cervicals 3-6 have deeply opisthoccelous centra, rather high and 

 narrow in proportion, with powerful zygapophysial processes. The inferior 

 lamellae of the transverse processes project downwards and forwards, and ex- 

 pand very slightly at the tip ; the width of this lamella increases somewhat in 

 C. 6 ; the superior lamellae project opposite the vertebrarterial canal. The sixth 

 and seventh cervicals apparently have slender elevated spines , in the remainder 

 the spines are low or tuberous. The centrum of C. 7 is subcircular in front 

 and broad posteriorly. 



The dorsals are represented by a number of vertebrae in the mid-region. The 

 centra are laterally compressed with distinct keels ; the zygapophysial facets 

 are very small and horizontal ; the metapophyses are well developed. The 

 length of the spines in the anterior dorsal region was apparently as in R.javanus. 

 No lumbars are found in this collection. 



Fore limb. — The scapula is very short and heavy. The general outline is 

 triangular ; the glenoid border is concave ; the coracoid border is convex ; the 

 superior border rises to a point above the spine; the upper third of the spine 

 shows a very stout recurved acromial process. 



The humerus is remarkably short and heavy, and is distinguished by the un- 

 usually elevated position of the deltoid ridge, which is much higher upon the 

 shaft than in the recent rhinoceroses. The tuberosities are heavy and sessile ; 

 the external condyle is unusually prominent. The ulna has a deep, powerful 

 olecranon process and stout trihedral shaft, which is suddenly compressed in- 

 feriorly for the cuneiform articulation. The proximal and distal laces of the 

 radius are subequal ; the shaft is very slightly arched and closely united with 

 that of the ulna, giving this segment a very massive appearance. 



The structure of the manus is in keeping with the short and heavy upper 

 segments ; it is broader and more powerful than in any of the recent rhinoce- 

 roses. The three short, widely spreading digits are faced by rugose areas for 

 the attachment of powerful muscles. Mtc. III. is much the largest; the lat- 

 eral metacarpals, II. and IV., are short and directed outwards ; the phalanges 

 are short and wide, especially the distal series. As in all tridactyle forms the 

 carpal displacement is extreme; the scaphoid covers the whole upper surface of 

 the magnum anteriorly; the lunar is rather small, and rests anteriorly wholly 

 upon the unciform ; posteriorly the pivotal process of the magnum supports 

 the lunar; the cuneiform is high and narrow. The trapezium is missing in 

 both the carpal series before us, but is indicated by the usual facets upon mtc. II. 

 and the trapezoid. The magnum is broad and quadrilateral. The unciform 

 has an unusually wide mtc. III. facet, and is vertically compressed. 



