Br. F. A. Dixey on the GeoyrapJiiad Factor in Mimicry. 209 



forms of Prioneris that so closely resemble them. D. 

 eucharis Drury (fig. f2), as is well known, is widely dis- 

 tributed ill the Indian region. In Southern India and Cey- 

 lon it is joined by P. situ Feld. (fig. 13), which according 

 to Fruhstorfer, flies in company with the Delias, and rests 

 just like the latter with closed wings on the flowers of the 

 Lantana. D. belladonna Fabr. (fig. 14) and P. thestylis 

 Doubl. (fig. 15) form another geographical mimetic pair 

 from the mountainous districts of northern India. In 

 Borneo we have D. indistincta Fruhst. (fig. 16) and its 

 very exact copy P. cornelia Vollenh. (fig. 17). Other 

 mimetic pairs not here figured are D. eyialea Cram, with 

 P. hypsipyle Weym. of Sumatra, and D. crithoe Boisd. 

 with P. autothisbe Hiibn. of Java. The two latter species 

 are said by Fruhstorfer to visit the flowers of chichona 

 in each other's company. 



A remarkably interestuig mimetic series is shown in 

 figs. 4 to 11 of Plate VI. Fig. 5 represents the underside 

 of H. laeta Hew. of Timor, a butterfly whose aspect dift'ers 

 so greatly from that of its congeners as to have suggested 

 to Mr. Wallace the possible existence of a model belongmg 

 to the belisama group of Delias. Thirty-four years after 

 the date of Wallace's paper, the missing model turned up 

 in the person of a fine Delias discovered in Timor by Mr. 

 Doherty, and named D. splendida by Lord Rothschild 

 (fig. 4). Though the resemblance between the Delias and 

 the Hu'phina is deceptively close, there is yet a difference 

 to be observed in the fact that H. laeta possesses a row of 

 marginal scarlet s])ots on the hind-wing which are not to 

 ])e found in D. splendida. But before leaving Timor Mr. 

 Doherty completed the assemblage by finding another 

 Delias, named D. dohertyi, after its discoverer, by Lord 

 Kothschild (fig. G). In this butterfly the resemblance to 

 the two former species is close ; and it possesses, which D. 

 splendida does not, a row of scarlet spots running parallel 

 with the outer border of the hind-wing. On the other 

 hand, the scarlet costal streak, conspicuous in D. splendida 

 and //, laeta, is absent from D. dohertyi. The Huphina 

 therefore may be said to combine in itself two character- 

 istic features which are found separately in the two Delias 

 models. 



Wc may now turn to the islands of Lombok, Sumbawa 

 and Flores, where we find geographical representatives 

 of all three members of the Timor assemblage. It is inter- 



TRANS. ENT, SOC. LOND. 1920. — PARTS I, II. (,IULY) P 



