25 
size, the wings not glaucescent, the medial band entire, not bifid at its 
extremity, etc. Typical caesiata, as he rightly points out, has the 
dark medial band “bipartite on the costa” {loc. cit., p. 962). The 
ground colour of annosata is said to be hoary, the forewings irrorated 
with cinereous, the hindwings hoary whitish. Except at the first, 
when Staudinger {IStett. Ent Zeit., xxii., p. 396) erroneously gave it 
for an extreme phase of ab. glaciata, the name has always been rightly 
applied to the aberrations with the central area more strongly and 
uniformly darkened, but (like glaciata in another direction) it grades 
off into the typical forms through intermediates. 
Several years later, Guenee {hr. et Phal., ii., p. 271, 1858) 
published another “ species,” under the name of gelata. It was 
obtained from Iceland, and, as I shall show, was practically identical 
with glaciata, Germ., to which of course it must sink. But as Guenee 
examined a larger material than his predecessor, it is not surprising 
that the series should have included an interesting aberration, which, 
according to his wont, he describes as “ var. A,” but does not name ; 
nor is it surprising, considering the beauty of this form, that he should 
have selected it for figuring (pi. 11, fig. 6). What is surprising—or 
would be so, but that the caprice and vagaries of nomenclators are only 
too familiar—is that Staudinger {Cat., ed. ii., p. 187, 1871) should 
have chosen to employ the name of “ ab. gelata, Guen,” for the 
aberration A instead of for the form for which it was invented. That 
Guenee’s gelata is, for all practical purposes, a synonym of glaciata, 
Germ., is shown by his description of it as dull, fuliginous brown- 
black, with the fascite which border the central area “ hardly lighter 
grey” than the ground colour. Germar, as his figure and description 
show, happened upon a specimen with rather whiter hindwings than 
usual; Guenee’s form had them “silky pale grey.” On the whole, 
then, as will be seen by comparing the two summaries which I have 
given, gelata is simply a rather extreme phase of the darkened Iceland 
aberration glaciata, Germ. 
The beautiful extreme form, “ gelata var. A ” of Guenee, with the 
ground colour nearly white, and with practically no markings excepting 
the dark central fascia, has never yet been named. Staudinger first 
called attention to it in his “ Reise nach Island ” {Stett. Ent. Zeit., 
xviii., p. 257), indicating it as “ var. b. al. ant. niveis, area basali 
mediaque grisea nigris $ ? but not naming it. It is certainly 
recurrent in Iceland, though probably not frequent even there; 
Staudinger obtained two of the extremes {$ and J) in his visit to 
that country, and says {loc. cit., p. 258) that the} r were “ from the north 
of Siglufjordr, as in general this inclination to whitening is shown 
almost exclusively in examples from the north. In the lightest 
specimen from the south, the dusting is especially yellowish, particu¬ 
larly on the nervures.” Guenee seems only to have regarded two of 
the Iceland specimens -which he had seen as gelata, for he gives Iceland 
among the localities for caesiata also, and says of his new species : 
“ Island Coll. Mus. une $ provenant du voyage de la Recherche” 
and of var. A: “Mernes provenance et collection.” He describes the 
latter as “grey almost white, and without lines or atoms, with the 
basal and medial areas of a fuliginous black as in the type. Inferiors 
with a single line.” His figure agrees, showing precisely the same form 
as one Iceland example in the British Museum collection, and a 
