Papilio dardanus {mcropc) ami Acr/i'a jolmstoni. 287 



cenea on Fig. 11 of the same Plate. It is remarkably 

 distinct in the polytrophus $ f. hvppocoon 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. Pcqnlio dardanus, sub-species meropc $ f. diow/sos, 



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 p)olytroi)]tus 

 females from the Kikuyu Escarpment, but I have not 

 yet met witli an example. 



In dionysos the hind- wings are those of the meropx!' ^ f. 

 trophonms except that they are of a distinctly paler tint 

 and thus nearer to trimeni. The costal gap is also very 

 strongly marked. The fore-wings possess the black and 

 white coloration oi Itippiocoon, but with a primitive dimirm- 

 tion of the black markings which is very like trimeni. 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 trimeni in the 

 same collection. It is probable that dionysos was an 

 early variant from trimeni, presenting a mixture of the 

 characters which in other proportions were to be selected 

 into irophoniics on the one hand and hippocoon on tlie other. 



IV. The suh-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* lias examined 509 males 

 and 270 females in the Tring Zoological Museum. Ex- 

 cludins the forms from N.E. Africa and Madarjascar and 

 ordy considering the males Dr. Jordan finds south of 

 Sierra Leone five sub-species distinguished chiefly by tlie 

 extent of black on the hind-wings. ])ifferences in sex- 

 organs are confined to the valve-edges. Dr. Jordan's five 

 sub-species are as follows: — 



* Der Gegensatz zwisclien oeographisclier nnd niclitf^eograpliisclier 

 Variation. Zeitsch. f. wisseiischaft. Zool., BJ. Ixxxiii. JJr. F. A. 

 Dixey has very kindly lent me for the purpose of this nieuiuir an 

 abstract which he has prepared of this interesting paper. 



