( xcvii ) 



taken on the same day but in another colony. The fore- 

 wings were represented by two short wings, with traces of 

 veins, the hindwingt being very vestigial. 



Mimicry of Nychitona medusa, Boisd., by Leuceronia 

 PHARis, Boisd., extending to habits and flight. — Dr. F. 

 A. DiXEY exhibited specimens of NycJiitona and Leuceronia, 

 remarking on them as follows : — 



The resemblance borne by the curious African Pierine 

 Leuceronia pilaris, Boisd., to forms of the genus Pontia, 

 otherwise Nychitona, was observed by Doubleday in 1847. 

 His remarks were quoted by Trimen in 1889, but without 

 raising the question of mimicry. That the relation is a 

 mimetic one has been several times suggested since, and in 

 1908 I called attention to the special likeness between this 

 Leuceronia and the form of Nychitona, Cram., recently 

 described by me as subsp. wigginsi (Trans. Ent. Soc. Lond., 

 1915, p. 15). Another form of Nychitona from the Congo 

 is in some respects still more like L. pharis. An extract 

 from a letter lately received from Dr. G. D. H. Carpenter, 

 which Prof. Poulton kindly permits me to read, is interesting 

 as giving an instance of a view founded merely on an examina- 

 tion of museum specimens receiving independent confirmation 

 from an observer in the field. Dr. Carpenter writes as follows, 

 under date of July 6, 1915 : " Leuceronia pharis is also 

 abundant at times, when a brood comes out. I was amazed 

 that this is in the same genus as Leuceronia thalassina \ 

 General appearance, shape, habit and flight are totally 

 different. Thalassina (both ^ and $) frequently assembles 

 to drink at moist spots, often almost entirely by itself, but 

 sometimes mixed with others, whereas pharis is purely a flower 

 frequenter. In my own mind I had put it with Nychitona 

 medusa; its whole appearance and feeble build and manner 

 of flying suggested close relationship to medusa." 



Dr. Carpenter's field experience is especially valuable as 

 showing that the resemblance between the two insects is not 

 confined to their mere appearance, but extends to their habit 

 and manner of flight. Another point of interest in Dr. 

 Carpenter's account is that L. pharis is at times abundant, 

 which so far makes in favour of the association being Miillerian, 



PROC. ent. soc. lond., Ill, IV, 1915. G 



