Butterflies 219 



16. Wings above practically without, or with very faint markings 



17. 



Wings above with conspicuous markings 18. 



1 7. Anterior wings each with a black spot, on which is a light 

 dot. . . . Eurymus scudderi Reakirt, female. 



Anterior wings without such discal spots (common) 



Pieris napi oleracea Harris, male. 



18. Hind wings beneath very pale yellowish, without dark mark- 



ings; female with two conspicuous dark spots on disc of 

 fore wing above (the European cabbage butterfly, intro- 

 duced, now very abundant) .... Pieris rapae Linnaeus. 

 Hind wings beneath conspicuously marked 19. 



19. Wings above with few spots, much resembling P. rapae, but 



hind wings beneath, at least, marked with gray stripes 



along the veins Pieris napi oleracea Harris, female. 



Wings above more conspicuously spotted, with at least a 

 series of black or gray spots along the outer margin . . 20. 



20. Under side of hind wings with heavy greenish-gray markings 



along the veins, yellow on the actual veins, but these 

 radiating markings broadly interrupted on disc by a 

 white subcrescentic area (widely distributed in the moun- 

 tains, and extending to California) . . . Pieris beck.eri 

 Edwards. 



Rather similar but smaller, the markings on under side grayer, 

 less yellow, and not entirely interrupted; discal spot on 

 fore wings above narrow, little or not larger than subapical 

 spot (large and subquadrate, with a white pupil, in hcckeri) 

 (widely distributed; at Boulder taken by Elsie Foster, 

 May 8, 1922) . . . Pieris sisymbrii Boisduval. 



Male very lightly marked, almost pure white above, but the 

 discal and subapical marks present, pale gray; female 

 marked much as in the last, wings more pointed, marginal 

 spots of anterior wings triangular, with base on margin 

 (common, perhaps better considered a western race of 

 the next) Pieris occidentalis Reakirt. 



More heavily marked than occidentalis, the male with very 

 distinct discal spot, the female with large discal spot 

 extending to the costal margin (which is not the case in 

 beckeri); stripes along veins on under side of hind wings 



