34 PROCEKDINGS OF THE 



exoiirsiou to tlie suiTiiiiit of t]i(» Cnrcovado," nonr liin. At first 

 sijjlit tli(» model and the mimic are so precisely alike that we do 

 not wonder at AVesl wood's statement that the whole series wa*! 

 "without any variation of the least importance"'; but with a 

 closer examination it is at once seen that the red bar of n-dfo 

 j)hi/Uis is sharply outlined while that of nanna is gradually 

 transitional into the dark ground-colour. Thus one of the six 

 Opisogvmni is accounted for: the remaining five, all taken 

 Mch. •2-2A, 1829, at Porto Keal (Porto jS'a^ionale) on the 

 'J'ocuntins Kiver, came from outside and to the noith-west of the 

 area in which Eurchell captured erato pliyllis. All the dates in 

 Westwood's catalogue are here to be found on the specimens, so 

 that nothing is inissing from this part of the collection. Thei-e 

 five examples, although with a softly outlined red bar, are easilv 

 distinguishable from //. nanna, and if Professor Westwoud had 

 arranged the individuals geographicnlly he would certainly not 

 have maintained that the variation was without the least im- 

 portance. For directly a geographical arrangement is made there 

 separates out this little group of 5 individuals \\\i\\ patterns all 

 very much alike, and all differing from those of the 55 — 54 models 

 and 1 mimic — collected in another area lying to the south and east. 

 In these 55 the lower outer border of the broad red bar is produced 

 into two strongly marked projections or teeth. The same border 

 in the 5 indi\iduals from the north-west bears only the lower 

 Ijrojection and this shortened and rounded. Examples in the 

 collections of the British Museum and Mr. W. J. Kaj'e agree with 

 those collected by Burchell. The difference is distinct but it is 

 small — so small indeed that it had not only escaped the attention 

 of Westwood in the museum but also of Burcliell in the field ; for 

 the latter had noted concerning a specimen taken at Porto Ileal 

 on Mch. 2, 1829: ^^ Fajnlio. The brown-winged (/lorta '') witli a 

 red patch on the upper wings, is always found in shady woods 

 and forests. I have seen it in similar situations in every part of 

 I>razil J have visited." These words indicate that he looked upon 

 all the specimens as belonging to a single species. But the 

 difference, although small, is constant and forms the distinguishirg 

 feature of the north-western subspecies //. nanna hurchclli. Prom 

 this form there can be no doubt that nanna nanna has been 

 ])roduced to the east and south under the influence of the ex- 

 tremely abundant //. erato plnjllis. Dr. H. Eltringham has shown 

 in a jiapert which will appear in the Transactions of the Entomo- 

 logical Society for the present year that the male genitalia of the 

 two races are precisely similar although very distinct from those 

 of frato phyllis. and he also agrees that nanna certainly arose from 

 hiiirhtlli and not vice versa. We have then an excellent example 



» It is sliown, ill A»7>. Mncj. Xaf. If/s/.. 1910, pp. .%"-.'">. that by " Hurlu" 

 Burcliell iiieimt to iniplv a placo in tlip Katiricijiii " Helironii." 



t "On Specifif and Mimetic ReJationsliips in the genus Helicoiin!'. L." 

 Trans. Eiit. Soc. Lund., 191G, pp. lUl-148. plates xi-xvii. 



E. B. P.. Sept. 4, I'JK;. 



