Vol.. \ 



"'] PROCEEDINGS OF THE NATIONAL MUSEUM. 487 



what dilated beyond the middle and rather obtusely terminated. A 

 very distinct stont supplementary corneous process at base of clasper. 

 Expands 1.40 to 1.G0 (35 to 4() mm ). 



Habitat. — Colorado, California. 



This species has been referred as a variety of the eastern alia, but 

 incorrectly. It closely resembles it in maculation, but has a more ro- 

 bust thorax and slightly different habitus. The genitalia are also 

 different. More extended comparisons are made further on. 



Taeniocampa alia Gn., 1, 354, 1852. 



incrrfa Grt., Lists and Lit.; Dimraock,* Psycho, 1885, iv, 273; instdbilis Fitch, Tr. 



N. Y. Agr. S., 10, 343 (Orthotics); Grt., Buf. Bui., 2, 23. 

 coiifli'ens Morr., Pr. B. S. N. H., 1874, 159; Grt., C. E., 12, 187 (pr. syn.). 



Varies in ground color from pale luteous gray to dark grayish brown. 

 Median lines obsolete or very faint; t. p. line usually puuctiform. S. t. 

 line irregular, pale, preceded by a darker shade. A row of black ter- 

 minal dots. Ordinary spots large, pale ringed, reniform usually darker, 

 at least iuferiorly. Secondaries pale fuscous, powdery. Beneath pow- 

 dery, with more or less complete common line and distinct discal spot. 

 Head and thorax concolorous. The harpes of the male are suddenly 

 narrowed and curved toward tip, which at its inferior angle is pro- 

 duced into a long, straight, acute process. The clasper is long, slender, 

 regularly curved and acutely terminated. At the base there is an ad- 

 ditional small, slender corneous process. Expands 1.40 to 1.60 inches 

 (35 to 40 mi "). 



Habitat. — Northern, Middle, and Eastern States; Missouri. 



This species has been confounded with the European incerta (insta- 

 bilis) and it closely resembles that species in maculation. It is per- 

 haps possible to match specimens from both continents very closely, 

 but the American form is distinguished by a different habitus, not 

 easily definable, and also by the decidedly different genitalia. In the 

 European form the harpe narrows gradually, and the tip is obliquely 

 cut from each side, leaving the middle slightly projecting. The three 

 species, pacifica, alia, and incerta, are very closely related, but are un- 

 doubtedly distinct. Compared with paclfica, alia is less robust, the 

 thoracic clothing less dense, while the wings are apparently more 

 heavily clothed with scales. 



Mr. Morrison's species confluem is based on a specimen in which the 

 ordinary spots are confluent, and the primaries have the costa more con- 

 vex. The type is a female from Missouri and I have been unable quite 

 to match it with a male, though specimens of alia with confluent spots 

 are not rare. It is possible, but I think hardly probable, that a good 

 species is covered by Mr. Morrison's name. 



*This species is among those found by Mrs. Dimmock on Betula, 



