Vol. XXlv] ENTOMOLOGICAL NEWS. 115 



oring occurs and there is apparently an ingenious attempt to 

 mimic the white spots and dark veins with the means at hand. 

 The shading of the brown is wonderfully good. The veining 

 on the under side of striyosa's secondaries is black with traces 

 of ashen gray bordering. This is followed in obsoleta even to 

 traces of the gray border. On the primaries of obsoleta, while 

 the veining is black as against brown in strigosa, the black is 

 confined to the veins and is not conspicuous. 



On the under side of strigosa there is what appears at a 

 slight distance to be an irregular black and white line across 

 the secondaries. The combination forming this consists of a 

 black-bordered white spot midway on the costa, the heavy 

 black discocellulars irregularly bordered with grayish-white 

 blotches, and, on the males, the scent pouch which is black cen- 

 tered with white. In approximately the same position on obso- 

 leta is a heavy black line with the inner edge bordered with 

 white which is broken up by the black veins into a row of white 

 spots. From its location it reminds one of the white bar of 

 L. arthcmis, which has been almost obliterated. 



This black line and the white spots "show through" on the 

 upper side of the wing and is not in harmony with the close 

 mimicry otherwise displayed. 



My theory concerning this feature is that in the attempt to 

 mimic the under side of strigosa this bar and the spots were 

 retained and that they persisted on the upper side also. A sim- 

 ilar attempt is made on the primaries to imitate the white spots 

 of strigosa. Here the black bar is nearly eliminated except near 

 the costal edge. The black and white show through on the 

 upper side also, but assist at this point in the mimicry. In 

 addition to these points all possible traces of white in arthc- 

 mis, and the pale blue lunules in the borders also, are empha- 

 sized in white on obsoleta in order to give as much as possible 

 the appearance of a considerable number of white spots on the 

 wings. 



In support of my theory I would suggest that the Danaidas 

 nearly always keep their wings folded, with the under sides 

 showing, when they are at rest or feeding on flowers in the 

 open. Why should not obsoleta attempt the mimicry of this 

 side at the expense of the other ? 



