288 Professor E. B. Poulton on Mimetic Forms of 
(1) P. cenea. S. Africa. Transition to next form in 
geographical position and morphological character is 
complete. 
(2) P. tibullus. Delagoa Bay northwards to Mombasa ; 
west limit unknown, but occurs in Uganda. 
(3) P. polytrophus. B. E. Africa. 
(4) Transitional forms from Victoria Nyanza. 
(5) P. dardanus dardanus. Unyoro to west coast. 
Congo specituens are larger, as in some other cases. 
Dr. Jordan furthermore states that P. dardanus is not 
sharply marked off into geographical forms. Hast and 
west coast examples can be distinguished, but neither 
assemblage is a complete unit. It is significant that 
the valve-process is generally present in eastern and 
absent from western forms. 
In the following pages I have followed Dr. Jordan’s 
conclusions and terminology with the single exception 
that I have called the fifth sub-species dardanus merope 
instead of dardanus dardanus. 
V. The origin of the mimetic female forms of Papilio 
dardanus /vom the ® f. trimeni. 
There can be little doubt that all the well-known mimetic 
females of dardanus as well as the latest discovery 
planemoides originated by modification of this primitive 
female form, either directly or by the combination and 
development of characters on their way to produce other 
forms. I propose to consider the evolution of these forms 
in the order of specialization, beginning with the most 
primitive :— 
(1) Mippocoon. ‘The relationship of hippocoon to triment 
is at once seen by comparing Fig. 2 with Fig. 1 on Plate 
XVIII. The transformation is remarkably direct and simple, 
consisting merely in the greater intensity and sharpness of 
black markings already distinctly indicated in trimeni, and 
in the alteration of the pale yellow tint of the latter into 
white. There are four examples of this form from the 
Escarpment in the Hope Department. The other three 
are fairly represented by the figure of the fourth on 
Plate XVIII, Fig. 2, and it is “rather surprising that 
none of them possess an indication of rudimentary “ tails.” 
It cannot be doubted however that hippocoon is by far 
