A single male specimen of a Colotis which does not seem to answer to any known species was captured by Mr. C. W. Wykeham in June, 1977, when he was serving on the South West African Northern Border, at the Rua Cana Falls. This butterfly shows affinity in certain respects to C. agoye bowkeri (Trimen) and C. eris eris Klug, but also differs very markedly from both these species. It is apparently more closely related to eris. The male genitalia have been dissected and several differences have been found in comparison with those of the other two species - in, for instance, the uncus, valves and aedeagi. The genitalia are closer to those of eris. In the opinion of Dr. C. B. Cottrell, to whom the dissections have been shown, the points of difference concerned are of considerable significance. In the case of the new insect, the aedeagus itself is remarkably small.