Abstract
A new chameleon is described from Marsabit Mountain in the northern frontier district of Kenya. On the basis of external morphology it becomes an additional member of the Chamaeleo bitaeniatus complex as defined by RAND (1963). However an annulated rostral horn which is present in male specimens, provides further evidence of the close relationship between this group and the east and central African three horned chameleons, a hypothesis suggested by HILLENIUS (1959), and supported by studies on lung and hemipenal morphology by BÖHME & KLAVER (1980), KLAVER (1981), and KLAVER & BÖHME (1986).