AMERICAN LEPIDOPTERA. 



19 



Hab— Nova. Scotia, Hudson's Bay Territory, southward to Vir- 

 ginia, west to Colorado. Dates in New York range from early in 

 July to late in August. In Illinois from the middle of July to the 

 beginning of September. 



This is the species that is ordinarily named nictitans in collections 

 and, compared with the European examples of this species, it is 

 almost impossible to say where the difference comes in. Superficially 

 the markings are almost alike, and are certainly well within what is 

 considered the ordinary range of variation. The antennae in the 

 male are very much alike, but the European examples are much 

 more strongly ciliated than the Americans. The difference in the 

 sexual characters has already been alluded to and need not be de- 

 tailed again here. Our species seems, as a whole, to be a trifle more 

 heavily built ; but otherwise, and judging from superficial characters 

 alone, their separation would hardly be justified. The range of 

 variation in the species is not great ; the difference in ground color 

 is not particularly startling, although by placing the extremes to- 

 gether it is seen to be quite marked. There is a tendency to a vio- 

 let tint in the s. t. space. In some cases the ordinary spots are both 

 contrastingly paler and more rusty than the rest of the wing. In 

 others there is hardly any difference to speak of. Finally, we may 

 have examples in which the reniform becomes entirely white, and 

 occasionally a specimen in which the orbicular also is of that shade. 

 This species is the most common of those found in this country and 

 deserves more attention than has been given to it heretofore. 



Il> rtroecia pacifica a. sp., pi. 1, fig. 6, % genitalia, 



This is the Californian representative of the European nictitans, 

 and resembles the latter almost as closely as does its Atlantic rela- 

 tive. There is a difference here, however, which is quite noticeable 

 when a good series of examples is under consideration. The Pacific 

 Coast form is uniformly more chunky, the body is more heavily 

 built, the thorax is squarer and the primaries are shorter and com- 

 paratively broader. Altogether it looks like a much more com- 

 pactly built species. In average size it is smaller than the eastern 

 form, but the wings are less pointed. So far as markings go there 

 is not much difference, and certainly none that would be considered 

 as of specific value. In all the examples before me, both sexes 

 being represented, both the ordinary spots are rather contrastingly 

 yellowish, and none of them show the least trace of white. The 



TRANS. AM. ENT. SOC. XXVI. MAY - 1899 - 



