Philpott. — Protective Resemblance in N.Z. Moths. 215 



thus situated, and on rough brownish bark is extremely incon- 

 spicuous. Vitiosa is also hard to detect under similar circum- 

 stances, and on moss-grown trunks plena and insignis are alike 

 unnoticeable. Such species as lignana, pelistis, composita, and 

 steropastis would be well protected about the roots of grass, 

 while the uniform brown colour of infensa blends admirably 

 with the underside of dead bark, and in this position I have 

 several times found it. The strikingly contrasted black and 

 green colouring of exquisita might be quite inconspicuous on a 

 lichen-grown trunk, but the insect is so rare as almost to lead 

 one to think that its striking appearance has had an adverse 

 effect on the species in the struggle for life. Octans is also 

 exceedingly rare, but two examples having been taken so far. 

 In this instance, however, the rarity of the species in collections 

 is probably due in great measure to the perfection of its resem- 

 blance to its environment. The type specimen was found on 

 a rough limestone rock, and its presence was only revealed bv 

 the closest scrutiny. 



Bityla defigurata. 



In common with Melanchra infensa, this species has a liking 

 for resting under pieces of dead bark ; in fact, I have several 

 times found small colonies hibernating under one flake of bark. 

 Its uniform dark-brown colour is very suitable for such a resting- 

 place ; and B. sericea would also be protected in a like situatioji. 



Rhapsa scotosialis. 



This is a dead-leaf-mimicking species. The light and dark 

 points on the forewings help to carry out the resemblance. The 

 moth is slow and feeble of flight, and if pursued often drops 

 to the ground aiid remains motionless. 



Tatosoma and Chloroclystis. 



Nearly all the species of these two genera are more or less 

 greenish in colour. They are spring and summer insects, and 

 frequent bush. It is worth noticing that in Tatosoma, where 

 the hindwings are small and covered by the forewings when 

 the insect is at rest, the hindwings exhibit n^ protective colour- 

 ing, but are pale dull-yellowish or grey. In Chloroclystis, how- 

 ever, where the hindwings are exposed in repose they partake 

 in a marked degree of the colour and markings of the fore- 

 wings. This interesting fact is noticed by Mr. Hudson* wlieu 

 speaking of Elvia glaucata, the beautifiil white- and- green lichen- 

 mimicking species. The tendency of some forms of the genera 



* " New Zealand .Motlis and BntterHies." p. 4(1. 



