104 VARIETIES OF NOCTILK 



form with almost obsolete markings. It is remarkable that in the 

 marshes in this neighbourhood (Greenwich) the greater number of 

 specimens are dark reddish-brown or reddish-grey, while at Deal a 

 large percentage are mottled-grey or reddish forms. Those at Kings- 

 down have a penchant for settling on the flowers of Centaur ea scabiosa, 

 and look like a small Eremobia ochroleuca, being of a pale ochreous 

 colour with a reddish tinge and almost always of the brown form. 

 The reticulated or mottled form I have termed reticulata, and have 

 added fusca, bnmnea, and rufa to distinguish the different forms. The 

 H- i-like mark which is characteristic of so many allied species is found 

 generally in the group with the darker base, but the mark is scarcely 

 ever traceable in the mottled forms. The var. vinctuncula of Hiibner 

 shows a strange development of the central transverse line separating the 

 basal from the outer area. The stigmata vary considerably ; in the 

 unicolorous form they are scarcely noticeable, being generally of the 

 same shade as the ground colour, while in the mottled variety they 

 generally (the reniform more especially) stand out strikingly pale. Of 

 the general variation of this species we read in Humphrey & West- 

 wood's ' British Moths,' p. 180 : " This is another extremely variable 

 species which in the typical variety has the basal half brown-coloured 

 or blackish, with clouded markings, whilst the apical portion is ashy- 

 white with the apical margin brown." " In other varieties the 

 general colour of the wing is more uniform, and either pale reddish- 

 brown or dull straw-coloured with the central portion darker and 

 bearing the characteristic markings ; others, again, have the wings 

 reddish and the apical margin blackish and undulated." " The hind 

 wings vary in tint according to that of the fore wings, but have the 

 margin dusky." 



The following is a classified list of the principal varieties of 

 bicoloria. Other incidental varieties may occur as var. vinctuncula of 

 Hiibner, also intermediate forms, but the former must be treated 

 separately, and the latter will generally be found allied very closely 

 to one or other of the varieties mentioned in the following table : 



A. Ground colour whitish-grey. 



1. With outer half paler than basal half = var. pallida. 

 2. Mottled, distinct transverse lines and stigmata = var. insulicola, 



Stdgr. 

 3. Unicolorous var. albicans. 



B. Ground colour greyish-fuscous. 

 1. With outer half paler than basal half = bicoloria^ ill. (= humeralis, 



Haw.). 



2. Mottled, distinct transverse lines and stigmata = var. reticulata. 

 3. Unicolorous = humeralis, var. y., Haw. 



C- Ground colour ochreous- or reddish-brown. 

 1. Outer half pale whitish grey = var. furunculd, Haw. 

 2. Mottled var. brunnea-reticulata. 

 3. Unicolorous = var. terminates, a. and {$., Haw. 



D. Ground colour pale reddish-ochreous. 



1. Outer half paler reddish-grey = var. pulmonarice, Dup., Gn. 

 2. Mottled = var. rufa-reticulata. 

 3. Unicolorous = var. rufuncula, Haw. 



