COREMIA PEKHUGARIA, llAW. ANU C. tKlDENTAtllA, HAW. IID 



the dark mark on the underside of unidentaria, near the base of the costa, 

 generally so conspicuous, is either weak or wanting in ferrugaria. It 

 is also tolerably certain that no form of unidentaria corresponds at all 

 to the extreme striated forms oi ferrugaria, indicated by Staudinger as 

 ab. spadicearia (" fascia media in strigis dissoluta "') or by Haworth as 

 salicaria (" obsolete strigata?, nee fasciataj "). 



Variation. — Both s^Decies are extremely variable, and it would not 

 be difificult to occupy a whole paper with studies of their variation. A 

 few general observations under this head seem worthy of being first 

 brought into prominence : — 



1. — As is usual in closely-allied species, the variation is largely on 

 parallel lines. 



2. — The variation of ferrugaria, Haw., is largely geographical ; that 

 of unidentaria, much less so. 



3. — On the other hand, the influence of heredity, exceedingly strong 

 in both species, is shown even more strongly in unidentaria ; so that 

 while the red and black forms exist together in most localities, yet the 

 black forms hardly ever throw red in their progeny. 



I will next deal, as well as time permits, with the variation of each 

 species separately. 



As I have ah-eady shown under the head of synonymy, I regard 

 the red forms as furnishing the type of what we call unidentaria. 

 Avoiding the doubtful name ferrugata, we may call this type corculata 

 Hfn., when unidentaria Haw., from its general constancy, is well worthy 

 to be dealt with as ab. unidentaria, in which light, rather than as a 

 distinct species. Dr. Staudinger is now inclined to regard it. Packard, 

 the American entomologist, speaks of it as " a good example of 

 melanism." 



Hufnagel's description of corculata, is as follows : — " Eeddish-brown, 

 on the outer margin a black C, at the base yellowish-grey." This of 

 course is so vague as to be practically useless, but "reddish-brown" 

 agi'ees well enough with some of the "purple " forms, to allow of our 

 uniting this name with ferrugata, Linn., and leaving the well-known 

 name of unidentaria, to the black forms. The American red specimens 

 (ferrugata, Packard), certainly belong to this species, and seem to have 

 the central fascia generally narrower than is common in European 

 forms ; my warmest thanks are due to Mr. H. F. Wickham, of Iowa 

 City, for my examples, which he took great trouble to procure, at very 

 short notice. 



There is a somewhat rare variety of ab. unidentaria, unknown to 

 Haworth, which deserves notice, namely the var. coarctata, WaiTcn. 

 This has the central fascia very much attenuated throughout, sometimes 

 reduced to hardly more than a thread ; there are two in the British 

 Museum collection, Captain Kobertson has one, Mr. Fenn another, Mr. 

 Machiii a very beautiful example, and two others have recently been 

 exhibited at our London Societies. 



Borkhausen's spadicearia was described from a single specimen, and 

 that apparently a somewhat rare form of spadicearia, W. V. We must 

 therefore take the type of spadicearia (z^ ferrugaria. Haw.), to be (as 

 Borkhausen describes it) a form with a mingled ochre and pale brown 

 ground colour, a broad brownish-red band lighter in the middle, 

 mixed with whitish and traversed with brown lines, the discoidal spot 

 distinct. As it appears to be the earliest name not otherwise pre- 



