96 



for larvae later than this to feed upon. Mr, Wright, at my request, 

 has watched the appearance of Piasus the present season, 1883, 

 at San Bernardino, southern California, and has sent me many- 

 examples (35 $ 12 ?). Evidently, there, there are two distinct 

 broods. The first examples were taken in February and March, 

 the last from i8th April to 2d May. All of a sudden the species 

 became abundant from i8th April, after an interval of several 

 weeks, during which none were seen. I find no perceptible 

 difference between the ^ ? of the two broods, except that in the 

 earlier one appears the female before spoken of, which resembles 

 Neglecta instead of Violacea ; of the males, there are several indi- 

 viduals, which, if taken in W. Va., I should consider Neglecta. As 

 I look at the matter, Piasus is probably an offshoot of Neglecta or 

 Pseiidargioliis, and occasionally there is a reversion to Violacea in 

 some characters.] 



Summing up the facts as related, with such inferences as the 

 best observations at command will justify, the history of the 

 species treated of will take shape as follows : 



1. The winter generation, in its most northern localities, is 

 one-brooded, and at same time dimorphic ; Lucia and Violacea. 



2. At a certain line, moving southward, say at or about lat. 45°, 

 on the Atlantic, a second generation, Neglecta, appears; and the 

 first, or winter, generation has become trimorphic: Lucia, Mar- 

 ginata, Violacea. 



3. At another line, say at or about lat. 38°, on the Atlantic, 

 two of the forms of the first generation are suppressed, viz. : 

 Lucia and Marginata ; and an entirely new form comes in, re- 

 stricted to one sex: viz., the black male of Violacea. 



3. But in lat. 40^, at the west, in Colorado, at high elevation, 

 the original dimorphism prevails, Lucia 3.nd Violacea; though the 

 latter has acquired the black male, identical with that of the east. 



5. At another line, say about lat. 33s in Arizona, Violacea is 

 replaced by a modified form, Cinerea, and the black male ap- 

 parently has disappeared. 



6. On the Atlantic, from about lat. 40^ or 39"^ and south, 

 a second summer form is interpolated : viz., Pseudargiolus, from 

 which proceeds a partial generation only the same year. 



7. This partial generation produces chrysalids, which hyber- 

 nate, and in the spring disclose a part of the butterflies of the 

 first generation, or Violacea. 



8. But most of the butterflies of the first generation are di- 

 rectly descended from the first generation of the year before. 



9. The first generation produces a partial second the same 

 year: viz., Neglecta, and this probably produces chrysalids 

 which hybernat,e to give butterflies of the first generation 

 in the spring. The first generation is therefore made up from 

 two and, probably, three distinct sources. 



10. The interpolated summer form, Pseudargiolus, is very 



