40 IOWA STUDIES IN NATURAL HISTORY 



7. Under surface of secondaries very pale, without sharp contrasts . philetas 

 Maculation of under surface contrasting; under surface often pow- 

 dered with brown scales syrichtus 



8. Basal third of wings dark 9 



This area not more than slightly dark shaded 10 



9. Secondaries with a subterminal esries of large white crescents 



ericeteorum $ 



These crescents much reduced domicella 



10. Cell of secondaries below clear white nivella 



Cell more or less brown 11 



11. Secondaries with broad smooth brown shades below 12 



With a definite yellowish brown pattern, no broad shades . . ericetorum $ 



12. Inside of outer shade oblique, almost straight. ., laviana 



Inside of outer shade curved with outer margin of wing maeaira 



1. HESPERIA CENTAUREAE (Plate I, Figure 2) 

 Eesperia centaureae Bambur, Faun. Ent. Andal. n, 315, pi. 8, f. 10, 1840. 

 Eesperia wyandot Edw., Proc. Ent. Soc. Phil, u, 21, pi. 5, f. 4, 1863. 

 Seudder, Butt. New Eng. n, 1542, 1889. 

 Holland, Butterfly Book 327, pi. xlvii, f. 13, 1898. 



N. Europe; Labrador, June and July. Ontario, Canada, May, July. 

 New Jersey and Virginia, April and May. North Carolina, April. Colo- 

 rado, August, 13000 ft. Male with costal fold and tibial tuft. 



2. HESPERIA RURALI8 



Syrichtus ruralis Boisd., Ann. Soc. Ent. France (2), x, 311, 1852. 

 Syrichtus caespitalis Boisd., op. cit., p. 312. 



Eesperia ricara Edw., Proc. Ent. Soc. Phil, iv, 203, pi. I, f. 2, 1865. 

 Syrichtus petrems Edw., Trans. Am. Ent. Soc. hi, 215, 1871. 

 Holland, Butterfly Book 328, pi. xlvii, f. 14, 1898. 

 Wright, Butterflies of the West Coast No. 458, pi. xxxi, 1905. 

 Oberthiir, Etudesde Lep. Comp. vr, 339, pi. cxxxvii, ff, 1204, 1205, 1212, 

 1912 (types of caespitalis and ruralis). 



Western North America from Texas to Alberta, April to July. 



A smaller, darker species than the preceding. Male with fold and tuft. 



3. HESPERIA XANTHUS 



Pyrgus xanthus Edw., Field and Forest in, 142, 1878. 

 Holland, Butterfly Book 328, pi. xlvh, 15, 1898. 



Colorado, July. Xanthus very closely resembles ruralis but most speci- 

 mens have the subterminal maculation of the secondaries poorly defined 

 and reduced as noted in the key, and the males lack the costal fold. 



4. HESPERIA MACDUNNOUGHI 



Syrichtus macdunnoughi Oberthiir, Etudes ix, (2), 86, pi. cclxiv, f. 2205, 



1913. 

 B. & MeD., Contributions m, (2), 122, pi. x, f. 14, 1916. 



