5^ Bulletin American Museum of Natural History. [Vol. X, 



the Hippopotamus ; girth (9' 2") exceeding that of R. unicornis 

 (8' 9") ; chest section deep and heavy, rather than rounded as in 

 R. unicornis. 



Scapula very characteristic, triangular in contour, with pointed 

 upper border ; narrow supraspinatus and very broad, triangular 

 infraspinatus fossa ; acromion placed midway on spine, reflected 

 backwards, so that attachment of deltoid and trapezius muscles is 

 elevated. Coracoid process forming a prominent rugosity for 

 short head of biceps ; bicipital tendons passing through a double 

 osseous groove upon front of humerus (as in R. unicornis, R. bi- 

 cor/iis and R. simusY''^ and inserted distally in a prominent rugosity 

 upon front of radius. Humerus exhibiting prominent rugosity 

 for subscapularis muscle interior to inner tendon of biceps ; 

 greater tuberosity consisting of a large incurved hook for supra- 

 spinatus muscle, and a separate and distinct knob for infraspinatus 

 muscle ; powerful deltoid ridge, everted but not hooked ; distally 

 a large external condyle for extensor muscles, which exhibit 

 rugose insertion areas in the proximal ends of metapodials. 



Pelvis with ilia arching over and coalescing above the five sacral 

 vertebral spines, affording a stout area of origin for latissimus 

 (lorsi, erector spines and gluteits maximus muscles, correlated with 

 support and propulsion of the enormous abdomen ; a foramen 

 piercing the posterior superior border of the ilium. Femur with 

 rugose but not very prominent greater trochanter; lesser trochan- 

 ter for insertion of gluteus maximus muscle, much less promi- 

 nent than in R. unicornis, and not hooked ; third trochanter not 

 prominent. Pubis and ischium more slender than in R. unicornis. 

 Tibia with a characteristic fissure in the cnemial crest dividing it 

 into two distinct tuberosities for patellar tendons (unlike single 

 crest of R. unico> nis and A. malacorhinus). Fibula fused with 

 tibia in aged individuals. 



1 Busk' On the Ancient or Quaternary Fauna of Gibraltar,' Trans. Zobl. Soc, 1877, p. 97. 

 '■^ De Blainville, ' Osteographie,' Atlas 3, Gen. Rhinoceros, PI. iv. 



