Papilio dardanus (merope) and Acrxa johnstont, 287 
cenea on Fig. 11 of the same Plate. It is remarkably 
distinct in the polytrophus  f. hippocoon shown on Plate 
XVIII, Fig. 2, although barely recognizable in the same 
forms from the west coast seen in Figs. 2 and 3 of Plate XIX. 
III. Papilio dardanus, sub-species merope § f. dionysos, 
Doubl. 
Before proceeding to consider the origin of the mimetic 
female forms of dardanus it is necessary to say a few words 
of this remarkable and primitive variety which is not 
uncommon on the west coast. It is very probable that it 
also occurs among the wonderful series of polytrophus 
females from the Kikuyu Escarpment, but I have not 
yet met with an example. 
In dionysos the hind-wings are those of the merope $ f. 
trophonius except that they are of a distinctly paler tint 
and thus nearer to ¢riment. The costal gap is also very 
strongly marked. The fore-wings possess the black and 
white coloration of hippocoon, but with a primitive diminu- 
tion of the black markings which is very like ¢viment. In 
fact in one specimen (Cameroons: Cutter: 1869) in the 
Hope Department the oblique bar dividing the two chief 
white markings of the fore-wing is even less developed 
than in any of the five specimens of ¢riment in the 
same collection. It is probable that dionysos was an 
early variant from ¢rimeni, presenting a mixture of the 
characters which in other proportions were to be selected 
into ¢trophonius on the one hand and Aippocoon on the other. 
IV. The sub-species of Papilio dardanus (= merope). 
Before discussing the origin of the mimetic female forms 
it is necessary to consider the division of dardanus into 
sub-species. Dr. Karl Jordan* has examined 509 males 
and 270 females in the Tring Zoological Museum, Ex- 
cluding the forms from N.E. Africa and Madagascar and 
only considering the males Dr. Jordan finds south of 
Sierra Leone five sub-species distinguished chiefly by the 
extent of black on the hind-wings. Differences in sex- 
organs are confined to the valve-edges. Dr. Jordan’s five 
sub-species are as follows :— 
* Der Gegensatz zwischen geographischer und nichtgeographischer 
Variation. Zeitsch. f. wissenschaft. Zool., Bd. Ixxxiil. Dr. F. A. 
Dixey has very kindly lent me for the purpose of this memoir an 
abstract which he has prepared of this interesting paper. 
