216 Zoology of Colorado 



from British America; it has received the name P. smintheus sayi 

 Edwards. 



In Europe, amateur collectors are greatly interested in the 

 variations and local races of Parnassius, with the result that many 

 minor forms have received names. Recently, some of our Colo- 

 rado specimens have come into the hands of these specialists, 

 and variations have been named leonhardii Ruehl and fermata 

 Bryk, the latter said to be from Denver. Some day, students 

 of genetics will take to breeding and crossing varieties of P. 

 smintheus, and then results of biological interest will certainly be 

 obtained. 



The extensive family Pieridae consists of mostly white or 

 yellow butterflies, more nearly allied to the Swallow-tails than to 

 any other group. The hind wings are quite without tails, and 

 the claws on the feet are bifid or two-branched, instead of being 

 simple as in Papilionidae. The following artificial table will 

 make it possible to recognize most of the forms. 



Large bright yellow butterflies without dark markings ... 1. 



Yellow or yellowish butterflies, with distinct black markings, 

 or at least black spots on front wings 2. 



Bright or deep orange, or yellow suffused with orange, and with 

 dark markings 9. 



White butterflies 10. 



1 . With an orange patch on anterior wings (taken by H. G. Smith, 



Jr., in Arapahoe County, a straggler from the south) .... 

 Catopsilia philea Linnaeus. 



Without such orange patches (a straggler from the tropics, 

 taken at Rosita) Catopsilia eubule Linnaeus. 



2. Apical region of anterior wings with a bright orange patch; 



small butterflies. (Boulder, Tolland, etc.) Antho- 



charis sara julia Edwards, female. 



No such orange patches 3. 



3. Apex of anterior wings broadly black; very small butterflies, 



expanse an inch to an inch and a quarter (common in the 

 mountains and on the plains) . . . Nathalis iole Boisduval. 



