448 Prof. E. B. Poulton on the Mimetic N. American 

 Transition between astyanax and archippds . . . 473 



ArGYNNIS (SeMNOPSYCHE) DIANA (fEMALE) A TERTIARY 



MIMIC OF LiMENITIS ASTYANAX 474 



LLMENITIS (ADELPHA) CALIFORXICA, THE NYMPHALIXE 



MODEL OF LIMEXITIS LOKQUIXI 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 akd that 



OP 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 ivi7if/s ...... 482 



(b) The fulvous mark at the coial angle of the hind-ivings . 483 



(c) The step-like break in the band at the junction of fure- 



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



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

 Slightly increased resemblance to the Adelpha pattern 



in the most southern examples of 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 Basilar el da) superficially re- 

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

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

 DanainPR and (2) the Tainlioninx : in the west (8) a 

 Nymphaline model generally placed in the South Ameri- 

 can genus Adc/j'ha, 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 



