HESPERIOIDEA OF AMERICA 11 



ed upon only in extreme cases. The neuration of the second- 

 aries is scarcely worthy of notice, though some exotic genera are 

 characterized by the presence of vein 5, which is usually absent 

 or very weak. 



The abdomen is of little service, though it aids in distinguish- 

 ing the genera of group A of the Pamphilinae from certan Hes- 

 periinae in that it projects beyond the secondaries in the former 

 and scarcely reaches their anal angle in the latter. 



The male secondary sexual characters in the Hesperiinae con- 

 sist of the costal fold on the primaries, tuft (always proximal 

 in our species) on the hind tibiae, tuft on the upper surface of 

 the secondaries and the two lobes found at the base of the abdo- 

 men on its ventral surface in Hesperia. In the Pamphilinae the 

 only form found in the North American fauna is the brand or 

 stigma on the disk of the primaries. While I agree with Wat- 

 son's treatment of these characters I believe that the great dif- 

 ference in form between some of the stigmata indicates suffi- 

 ciently different development of the species possessing them to 

 warrant their generic separation. Fortunately in our fauna this 

 character can be supplemented by others. It is necessary to 

 guard agains splitting on this basis, for many stigmata which 

 are superficially different may easily be seen to follow in their 

 fundamental structure a single type. 



The genitalia, especially of the males, are of great value in 

 making specific determinations, and similarity of genitalia often 

 affords an index of generic relationship. I have found several 

 apparent contradictions to the latter statement, and am there- 

 fore inclined to use it very cautiously until more is known about 

 the skippers, but still I hesitate to include in the same genus 

 species whose genitalia are of widely different forms. 



In attempting to work out the phylogeny of our existing 

 speces I have come to the conclusion that the subfamily Ismeni- 

 nae, made up entirely of old world species, represents the most 

 primitive existing form. The entire subfamily is characterized 

 by the upturned, appressed second joint of the palpi, very sim- 

 ilar to that of the Hesperiinae of group A, and the long, porrect 

 third joint which is unique. The antennae have a short shaft 

 and a long, moderately thick club with a long apiculus which 



