46 NEW ZEALAND MACRO-LEPIDOPTERA. 



Genus 5.— ELVIA, Walk. 



" Face smooth. Palpi rather long, straight, porrected, densely rough-scaled above and beneath, 

 terminal joint short. Antennae in male stout, flattened, bipectinated (2.}). Thorax somewhat crested. 

 Fore-wings with vein 6 from a point with 9, 7 from angle of areole, 10 anastomosing moderately with 

 9, 11 out of 10, running shortly into 12. Hind-wings with veins 6 and 7 stalked, 8 anastomosing with 

 7 from near base to near transverse vein." — (Me*yrick.) 



We have one species. 



ELVIA GLAUCATA, Walk. 



(Elvia glaueata, Walk. 1431 ; Feld. exxxii. 25. Elvia donovani, Fold, exxxii. 5. Elvia glaucata, Meyr., 



Trans. N. Z. Inst. xvi. 65.) 



(Plate VI., fig. 23 and 24 varieties.) 



This very pretty insect is generally distributed throughout the country. 



The expansion of the wings is about an inch. 



The fore-wings vary from pale green to dark .steely blue, rarely pale reddish-brown ; there is an 

 almost straight, black transverse line near the base; a broad curved line before the middle, shaded 

 towards the termen; then a straight line, breaking up into dots towards the dorsum, followed by a 

 conspicuous cream-coloured blotch near the casta ; this again is followed by a fine jagged cream-coloured 

 line ; there is a terminal series of black dots. The hind-wings are cream-coloured, tinged with steely 

 blue or green towards the termen ; there are a few obscure transverse lines and a short series of dots 

 from the dorsum. The apex of the fore-wing is very blunt, and the termen is slightly hollowed out 

 towards the tornus ; the termen of the hind-wings is deeply scalloped. 



This species is extremely variable. In addition to the variations above indicated, 

 the markings of many specimens differ considerably in intensity, and there are fre- 

 quently several large cream-coloured blotches towards the base or middle of the fore- 

 wings. 



The perfect insect appears from September till March, but is not a common species. 

 It frequents forest districts, and may sometimes be found at rest on tree-trunks, where the 

 beautiful colouring of its fore-wings closely imitates that of certain lichens, and renders its 

 detection in such situations extremely difficult. Unlike the insects included in the two 

 preceding genera, this species closes its wings when at rest, the anterior pair alone being 

 visible. These wings are not held flat, but are curiously folded longitudinally, and the 

 end of the abdomen is also curled upwards. By slightly raising the insect above the level 

 of the surrounding surface, this peculiar attitude considerably increases its resemblance to 

 a lichen growing on the stem or branch of a tree. It will also be observed that in this 

 species, which when at rest exposes only its fore-wings, these alone are protectively 

 coloured ; whilst in the genera, Chloroclystis and Phrissogonus, where both pairs of wings 

 are displayed, both pairs are protectively coloured. 



Genus 6.— HYDRIOMENA, Hb. 



"Face with somewhat projecting or loose scales, or with conical tuft. Palpi rough-scaled. 

 Antennae in male ciliated, rarely dentate or naked. Abdomen not crested, or with crests on two basal 

 segments only. Fore-wings with areole double. Hind-wings with 8 anastomosing with cell from 

 near base to beyond middle. (See Plate II., fig. 32 head, figs. 33 and 34 neuration of Hydriomena 

 dcltoidata.) 



"A very large genus, principally characteristic of temperate regions in both 

 hemispheres." — (Meyrick.) 



There arc twelve New Zealand species. 



