MIMETIC ASSOCIATIONS 



75 



This late addition to the species of Pseudacraea has only recently been described by the 

 above author, and is represented at present by only one example of each sex. The male 

 was taken about sixteen miles west of Shimba, near Mombasa, at an elevation of 1,200 feet, 

 and the female at Rabai. The Rev. K. St. A. Rogers, who captured the female, states that 

 in pattern and flight it was indistinguishable from P. aganice. The male was given to this 

 collector, who forwarded it to Oxford, and remarked on its resemblance to the male P. montana. 

 The female Ps. rogersi has a blue iridescence which is visible on the upper surface of the wings 

 when viewed in certain lights. This structural colour is also observable in some specimens of 

 the female of Pseudacraea hohleyi. Ps. rogersi is exceptionally interesting, completing, as 

 it does, the series of these Pseudacraeine mimics corresponding to the forms of the Planema 

 models. 



P. ELONGATA GROUP. 

 PLANEMA ELONGATA. 



Butler, Cist. Ent., i, p. 212 (1874). 

 Aurivillius, Ent. Tidskr., xiv, p. 283 (1893). 

 Hewitson {eurita), Exot. Butt. Acraea, pi. 5. f. 28 (1867). 

 Aurivillius, Rhop. Aeth., p. 120 (1898). 



Plate VII, Fig. 10, ?. 



This Planema was figured by Hewitson in 1867, who included the two sexes in the twelve 

 figures which he considered to be various forms of what he then called Acraea eurita. Butler 

 subsequently separated many of these forms into species, and to a pair of the present form 

 in the National Collection he gave the name elongata. The sexes differ considerably. The 

 male has much narrower fore-wings, rather darker in ground-colour, and with a tendency 

 to concavity in the hind-margin. The lower extremity of the discal band is less inclined 

 outwards towards the hinder angle than in the female, and is of a rich reddish-ochreous. 

 In the hind-wing there is a triangular patch of dark reddish-brown, the dark hind-marginal 

 border is narrower than in the female, and the discal area is rich reddish-ochreous with 

 black nervules and internervular rays. Hewitson's examples apparently came from the 

 Congo State. The pair in my own collection were received from Ogowe. 



PSEUDACRAEA RUHAMA. 



Hewitson, Ent. Mo. Mag., ix, p. 84 (1872). 

 — Exot. Butt (5 Diadema euryius), pi. 3, f. 8 (1868). 

 Butler (5 metaplanema) , Cist. Ent., i, p. 215 (1874). 

 Aurivillius, Rhop. Aeth., p. 177 (1898). 



Plate VII, Fig. 13, ?. 



P. ruhama was figured by Hewitson in 1868 as one of the many forms of his Diadema 

 eurytus, which he considered to be all varieties of the same species. In 1872 he described in 

 the Ent. Mo. Mag. a male butterfly which he named Diadema ruhama, and which he received 

 from Angola. This Professor Aurivillius considers to be of the same species as the form 

 of Diadema eurytus above mentioned. Evidently the two sexes of the Pseudacraea mimic 

 the corresponding sexes of Planema elongata. The species is extremely rare. There are two 

 specimens in the Hope Department at Oxford which are both females, and are sHghtly dif- 

 ferent in appearance from the example figured, which is in my own collection, the fore-wing 

 discal bar being less prominent and more suffused towards the hind-margin. In the National 

 Collection there are five males and four females. The male is smaller than the female, has 

 narrower wings, and the band in the fore-wings is narrower and reddish, instead of white 

 as in the female. 



K 2 



