UNKNOWN BIG CAT OF NAMIBIA?

In 1853 a book by Ray Galton appeared entitled Narrative of an Explorer in South Africa.  When in South-West Africa (now Namibia) he described an unknown species of cat which in some respects resembled a puma.  This animal was reported a number of times by other sources.  The natives were acquainted with it and said it was not dangerous to humans.  But what was it?  Is it still to be found?