BUTTEEFLIES OF THE DISTRICT OF COLUMBIA 95 



Smithsonian grounds. Its occasional presence in moist open fields 

 in company with the red admiral {Pyrmneis atalanta) has led me 

 to search for its caterpillars on the false nettle {B oehmeria) , though 

 without success. Elsewhere it feeds upon this plant. 



Seasons. — The question mark comes from its winter quarters to- 

 ward the end of April and early in May, and the ragged spring 

 individuals have all disappeared before the first of June. A second 

 brood (of the form uTubrosa) begins to appear in the first half of 

 June. Early in August fresh individuals of the dark form are seen 

 that probably represent a second summer brood. In the second week 

 in September the first individuals of the light autumn brood appear, 

 these continuing to emerge until well into October, when they go 

 into hiberation. 



In this region this butterfly appears to be partly two and partly 

 three brooded. In New England, according to Mr. Scudder, it is 

 two brooded, while in West Virginia, according to W. H. Edwards, 

 it is partly three and partly four brooded. 



Remarks. — The summer broods are made up almost exclusively 

 of the dark form {wnhrosa) in which the hind wings are almost en- 

 tirely dark brown, the tails on the hind wings are relatively short, 

 and the angle on the fore wings is only moderately produced. The 

 autumn brood consists almost entirely of individuals of the light 

 form {fdbricii) with the hind wings but little darker than the fore 

 wings, long tails, the angles of the fore wings greatly produced, and 

 a conspicuous violet edging to the wings. But I have taken dwarf 

 individuals of the dark form which have hibernated early in spring, 

 and individuals of the light form in the last week in June. 



Note. — Mr. Scudder said that the upper posterior lobe of the clasps 

 in the male is slightly shorter and less produced, and the upper basal 

 process is a little slenderer, in the dark form (umbrosa) than in the 

 light form {fahricii). Carl Heinrich has recently studied the male 

 genitalia in these two forms and found no differences. 



POLYGONIA COMMA (Harris) 

 Hop ME21CHANT 



Plate 11, Figures 3, 4 



Occurrence. — Frequent, though not very common, throughout the 

 District and surrounding country. It is most numerous in the woods 

 along the canal and Conduit Eoad to Great Falls, and is frequent in 

 the higher and drier woods in Rock Creek Park. It is casual in the 

 Smithsonian Institution grounds and about elm trees elsewhere in 

 Washington, and I have found the pupae on the trunks of elms on 

 the Constitution Avenue side of the New National Museum. 



