448 Prof. E. B. Poulton 07i the Mimetic N. American 

 Transition between astyanax and archippus . . . 473 



ArGYNNIS (SeMNOPSYCHE) DIANA (fEMALE) A TERTIARY 



MIMIC OF LiMENITIS ASTYANAX 474 



LIMENITIS (ADELPHA) CALIFORNICA, THE NYMPHALINE 

 MODEL OF LIMENITIS LORQUINI 475 



The southern Limenitis ■(Adelpha) bredowi a mimic 

 OF the Neotropical Adelphas . • . . . 478 



The Geographical distribution of the western species 

 OF Limenitis in N. America 478 



Relation between the pattern of L. lorquini and that 

 OF the non-mimetic L. weidemeyeri .... 478 



Mimetic resemblance stronger in the southern examples 

 of lorquini which are geographically coincident with 

 californica 481 



Differences between californica and bredowi are such 



AS TO promote a RESEMBLANCE BETWEEN THE NORTHERN 

 FORM AND LORQUINI 482 



(a) The shape of the wings 482 



(b) The fulvoKs 77iark at the anal angle of the hind-ivings . 483 



(c) The step-like break in the band at the jn/nction of fore- 



and hind-wings ....... 483 



(d) The external border of the hind-wing hand . . . 484 

 Slightly increased resemblance to the Adelpha pattern 



IN THE most. SOUTHERN EXAMPLES OP BREDOWI . . . 485 

 Has RECIPROCAL (DIAPOSEMATIC) MIMICRY BEEN ESTABLISHED 



BETWEEN CALIFORNICA AND LORQUINI ? . . . . 485 

 CONCLUSIONS : 



A. The Eastern Section of North America . . 487 



B. The Western Section of North America . . 488 



Introduction. 



The mimetic species of the North American Nymphaline 

 genus Limenitis (including BasilarcMa) superficially re- 

 semble, in the east and north, as suggested by Doubleday 

 (Gen. Diurn. Lep., ii, p. 275), models belonging to (1) the 

 Danainie and (2) the Fcqnlio7iina3 : in the west (3) a 

 Nymphaline model generally placed in the South Ameri- 

 can genus Adeljjilia, allied to Limenitis. 



A species of Limenitis, in many respects relatively 

 ancestral and probably resembling the form from which 

 the mimics arose, still exists in the east, and another in 

 the west. Hence the history of the transformation — 

 probably in every case very recent — can be made out with 

 exceptional clearness. 



The subject will be treated in the order in which the 

 models have been arranged above. 



I desire to thank Dr. F, Du Cane Godman, F.R.S., for 



