80 ZYG^NID^ AND BOMBYCID^ 



indeed it is quite possible that the figure here given of A. Dahurica may 

 be the $ of Walker's complkata. As points of specific difference, Grote, 

 who has examined Walker's type in the British Museum, notes a slight 

 difference in the coloration of the head, a larger amount of pale color 

 in the posterior wings, and the completeness of the terminal arctian 

 band on the primaries, which in Grote's description of A. Dahurica is 

 said to be obsolete on cell 3 (q. v.) There is no note of any difference 

 in the location of the markings on the primaries. Now both of these 

 species are from the same locality, and in a genus where the markings 

 are so notoriously liable to fusion or obsolescence it seems to me, 

 (without having seen the type of cfw/>//(ra/(/) that these differences are 

 not sufficient to warrant the creation of a new species. As will appear 

 in Part 5, A. achaia varies infinitely more than this, as do many other 

 insects of this group found on the Pacific Coast, among which may be 

 enumerated Antarctia vagans, {ptmciaia, Packard), Pseudohazis eglan- 



terina, Nemeophila alaskensis and Nemeophila ? Of the latter 



insect, one of the synonyms of which is Lithosia decia, Boisd., scarcely 

 any two specimens are exactly alike, and it is quite common from 

 California to Oregon. This extreme tendency to variation on the 

 Pacific Coast is a subject of very great interest, whether due to the 

 great variety of climate and conditions under which the insects live, or 

 to whatever other cause, and being so constantly reminded of the fact I 

 should gready hesitate to separate two insects on differences so slight as 

 those quoted by Mr. Grote. Indeed were I to do so it would be neces- 

 sary to make four or five species of what I knozv to be Arctia achaia, 

 Grote ; and two, if not three, out of Pseudohazis eglanterina. I there- 

 fore, while not including A. complkata in the synonymy o'i A. dahurka, 

 have but little doubt that the two insects are identical. 



