126 THE CANADIAN ENTOMOLOGIST 



The male genitalia exhibit in this case a good instance of specific 

 individuality. This modification exists in the terminal character 

 of the clasp, with the harpe, a stout sickle-shaped member, larger 

 than in any ally. Instead of the produced costal angle at the corona, 

 the margin terminates squarely and is prolonged below into a 

 curved hook or pollex; this section of the valva heavily spinose 

 as usual. The harpe arises in close juxtaposition and exceeds the 

 pollex so that these two points, unique in their nearness, may be 

 seen in the specimen without preparation of the parts. 



Habitat. — The type locality is the prairie environs of Chicago, 

 111., and the species doubtless enjoys a wide range through the 

 prairie zone supporting the food plant, though it has thus far eluded 

 collectors, apparently. A large series of bred specimens are under 

 observation, and a number have been labelled "paratype" as 

 representative for several collections. A male type and several 

 further paratypes remain with the author. Variation in ground 

 colour runs from a dark, almost blackish-purple, powdery efifect 

 to an even, rich, reddish tone, while one of the series showed the 

 stigmata much reduced. These conspicuous white markings, in- 

 clusive also of the basal spots, are similar with marginidens and 

 nephrasynthela, with a strong superficiality in the direction of the 

 latter. The larval features denote a relationship to cerussata, 

 while the genitalia denote a proximity with Californian species in 

 one direction, which might not be unexpected, as the food plant is 

 generically more at hom.e in the Southwest. 



The character of this food plant is such that the entry and 

 future operations of the larva produce little evidence along the 

 usual lines suggestive of Papaipema work. The egg overwinters 

 and the young larva emerges about the^ first of June. A con- 

 spicuous amount of frass is thrown out, but may be hidden in the 

 cluster of close-lying leaves which by reason of their spined edges 

 are not pleasant to handle. The flowering stem is mined to some 

 extent, though n:cst of the work is in the root-crown, the larva 

 working usually in more than one taproot. As old clumps consist 

 of several taproots, this is easy, also one clump may furnish several 

 larvae and these older plants are invariably selected for oviposition. 

 Fire plays a mcst important role in the economy of the species, 

 and the early failure of my co-labourers to meet with it was doubt- 



