LEPIDOPTEKA— PAP1LIONIDAE— A. AUSONIDES. 747 



alights frequently on the flowers of the wild mustard and other cruciferous 

 plants ; but as soon as the sun is well up, it darts away on prolonged flights, 

 and is rarely seen by the collector. 



" I observed it once in the vicinity of Washoe Lake, Nevada, in some 

 numbers, but the day was warm, and the insects extremely wild. Nothing 

 is known at present of the earlier stages." 



NATHALIS, Boisd. 

 NATHAL1S IOLE, Boisd. 

 Nathalis Irene, Fitch, 3d N. Y. Kep. 



N. Idle is found throughout the Southwestern States and in Colorado. 

 Specimens were also brought by the expedition from Utah, the most western 

 point from which the species has been recorded. In Colorado, at 7,500 feet 

 elevation, the species was met with about the 20th of June ; and a few days 

 later one or two were seen in the South Park. It is not uncommon in the 

 mountains, like several other species wliich at the East are rarely found 

 north of the cotton States, although, even in New England, they would 

 hardly be subjected to as great or such continued extremes of cold as in 

 these parts of Colorado. D. Berenice and E. Claudia are similar examples. 

 A partial explanation might be found in the supposition that some bird 

 which preys upon them or their larvre at the East may be absent in the 

 Rocky Mountains, though, as all birds reject the Danaidce, this will not 

 explain the occurrence of Berenice. 



ANTHOCHARIS, Boisd. 



ANTHOCHARIS AUSONIDES, Boisd. 



Anthocaris Ausonides, Edw., Proc. Eut. Soc. Phila., 1803. 

 Anthocaris Ausonoides, auct. Ainer. 



Taken by the expedition in Colorado, where, in June, it is quite 

 abundant throughout the mountain district, and may then be seen deposit- 

 ing its eggs upon wild Crutifcrm. The larva is yellow, striped longitud- 

 inally with lead color, and dotted with black granulations ; it attains its 

 growth early in July, and changes to a curiously horned chrysalis, pale 

 brownish in color, with a darker lateral line. The chrysalis tapers gradu- 



