HESPERIOIDEA OF AMERICA 59 



page 106, at the same time dividing it and naming one part 

 DaU<i. Such differences as he mentions between the two seem 

 to be slight and transitional through the series of species in- 

 eluded, and I therefore sink Dalla. The description of DaUa 

 does not apply to our species as well as Mabille's diagnosis of 

 Buflerm, so if the genera be separated again there is a possi- 

 bility that Butlen^, and not Dalla will still be applicable in 

 our region. 



Key to the species 



Under surface of secondaries immaculate pirus 



With a number of small pale spots microsticta 



With a few large spots polingi 



1. BUTLERIA PIRUS 



Pholisora pirus Edw., Field and Forest m, 119, 1878. 

 Colorado, Utah, Arizona; June, July, 



2. BUTLERIA MICROSTICTA 



Butleria mi-crosticta G. & S., Biol. Cent.-Am., Rhop. n, 464, pi. 92, ff, 1, 

 2, 3, 1900. 

 I have seen no specimens; the species is said to occur near the Mexican 

 border. 



3. BUTLERIA POLINGI 



Pyrgus polingi Barnes, Can. Ent. xxxii, 44, 1900. 

 Arizona, June and July. 



GROUP B 

 Ecij to the genera 



1. Wings broadly rounded Ancyloxypha 



"Wings more or less trigonate 2 



2. All wings trigonate ; male without stigma ; club of antennae 



about as long as shaft Oarisma 



]\Iales with stigma ; secondaries, at least, rounded ; club not 

 as long as shaft 3 



3. Secondaries rounded, primaries trigonate; club small 



Copaeodes 



Outer margin of primaries more oblique and rounded ; club 

 large, relatively long Adopaea 



