The Collaborative International Dictionary of English v.0.48:

Mahoohoo \Ma*hoo"hoo\, n. (Zool.)
   The African white two-horned rhinoceros (Atelodus simus).
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

umhofo \um*ho"fo\ ([u^]m*h[=o]"f[-o]), n. (Zool.)
   An African two-horned rhinoceros (Atelodus simus or
   Rhinoceros simus); -- called also chukuru, and white
   rhinoceros.
   [1913 Webster]