320 Explanation of Plates, 
Fic. 1b. Acrea johnstoni, form proteina, 9, from the same locality 
as 1 and la. Captured by Mr. Marshall, October 11, 
1905. The female exhibits a patch even larger than that 
of the male, and of a shape which approximates more 
closely to the model shown in Fig, 1. 
2. Planema poggei, Dew., ¢, from Buddu, between Entebbe 
and the mouth of the Kageru River, west shore of Lake 
Victoria Nyanza ; collected December 3, 1902—March 1, 
1903, by T. T. Behrens, R.E. This Acreine butterfly 
with its broad fulvous band crossing the fore-wing, and 
white band crossing the hind-wing is evidently the primary 
model of the particular variety of the semifulvescens, 
Oberth., form of A. johnstoni, shown in Fig. 2a. 
At the same time the latter exhibits a nearer approach 
to the planemoides, Trim., 2 form of Papilio dardanus, 
Brown., one of its co-mimics (compare Plate XX, 
Fig. 4), than it bears to the central model of the group, 
Planema poggei. 
2a. Acrxa johnstoni, form semifulvescens, Oberth., 9. From 
Taveta (about 2500 feet), British East Africa; May 15, 
1905, Rev. K. St. Aubyn Rogers. This form possesses a 
pure white patch on the hind-wings, while the inner 
area of the fore-wings is black instead of fulvous as in 
typical semifulvescens (Plate XXI, Fig. 3a). This form 
appears to mimic the planemoides female of Papilio 
dardanus more closely than any other member of the 
large group clustered round Planema pogyei (compare 
Plate X of the present volume, accompanying Mr.S, A. 
Neave’s memoir). 
3. Planema latifasciata, E. M. Sharpe, ¢ ; from Toro, W. 
Uganda (7-9000 ft.). November— December 1900; 
Major Rattray. This Planema is the model for the 
toruna form of johnstoni represented in the next figure, 
3a. Acrexa johnstoni, form toruna, H. Grose-Smith, ¢; from 
the same locality and date as the preceding. The 
mimetic likeness is strong in the deep rich brown of the 
inner area of the fore-wings and basal region of hind- 
wings in model and mimic, in the fulvous subapical 
band crossing the fore-wing and discal band crossing the 
hind-wing, and finally in the dark ground colour external 
to these striking markings. 
In all forms of Acrava johnstoni here represented (Figs. 
la, 1b, 2a, and 8a), the under-side exposed during 
prolonged rest, when most of the fore-wing is hidden by 
