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



cell of lorquini, is generally minute or altogether wanting 

 in weidcmeyeri. It is developed in the British Museum 

 series of the latter species as follows : — Large on the upper 

 surface in 1 male, of medium size in 1, minute in 7, and 

 absent in 5 : of medium size in 2 females, very minute 

 in 1, absent in 3. 



Nearly the whole of the above points of distinction 

 between the upper surface patterns of wcidemeyeri and 

 lorquini can be verified by the comparison of Figs. 1 and 

 10 with 6, 7, and 8, on Plate XXV. The example of 

 loeidemeyeri represented in Fig. 1 possesses an unusually 

 well-developed spot in the fore-wing cell, while Fig. 10 

 represents an individual in which it is minute, especially 

 so upon the left side. The relatively high development 

 of this spot in lorqttini is almost certainly ancestral, as is 

 the subapical series of white spots in the fore-wing 

 (less developed than in weidcmeyeri) ; for both interfere 

 with the mimetic resemblance to californica (compare 

 Figs. 2 and 3 on the same Plate). The submarginal white 

 spots, especially developed in the apical section of the fore- 

 wing hind margin of weidemeyeo'i, have almost disappeared 

 in lorquini. Faint traces can however generally be detected, 

 as in Figs. 6, 7 and 8. 



The difference in tint between the white band of 

 weidcmeyeri and the cream band of lorquini, californica 

 and hredoivi could not be shown by photography without 

 detriment to other parts of the negative. Mr. A. Robinson, 

 of the Oxford University Museum, got over the difficulty 

 by colouring the parts which should have been cream with 

 a wash of very dilute aniline colour in water. Plate XXV 

 has been prepared from a print thus treated. 



The under surface of lorquini differs from weide^neyeri 

 in the strong development of a dark rich mahogany-brown, 

 replacing more or less completely the bluish-grey tint of 

 the basal half of the hind-wing and of the submarginal 

 markings. So far as my experience goes this replacement 

 is on the average carried much further in the examples of 

 lorquini from Vancouver's Island. 



In those individuals of lorquini in which the suppression 

 of these pale markings is least pronounced, the inner row 

 of submarginal lunules — bluish-grey in the hind-wing, 

 white in the fore — is larger and more conspicuous than 

 in weidcmeyeri. 



