468 



EQUIDJE. 



The three existing genera of this suborder constitute distinct 

 subdivisions of considerably higher rank than ordinary families. 



Fig. 151. Bones of Ihe manus of : a. Horse (Equus cdballus), b. Rhinoceros 

 (Rhinoceros sumatrensis), c. Tapir (Tapirus indicvs). II, III, IV, V, second, 

 third, fourth, and fifth digits. U, ulna; B, radius; c, cuneiform; 

 I, lunar ; s, scaphoid ; u, unciform ; m, magnum ; td, trapezoid ; 

 tm, trapezium. (From Flower's ' Osteology of Mammalia.') 



They may, however, for simplicity be classed as of family rank, and 

 living forms may be distinguished thus : 



Only one digit developed in each foot Equidae. 



Three digits on each foot; one or two horns on the 



nose Rhinocerotidae. 



Four digits on fore feet, three on hind ; no 



horns Tapiridae. 



Family EQUIDSE. 

 Genus EdlTUS, Linn. (1766). 



The characters of the family may, for convenience, be included 

 in the description of the only living genus. In this each foot is 

 formed of a single digit consisting of a metacarpal or metatarsal 

 and three phalanges, the distal phalanx being surrounded by a 



