GEOMETERS. 



on the hind wings, is not unfrequently entirely 

 filled up by dark brown, and when this is 

 the case the lines themselves are scarcely 

 visible, but a broad brown band or riband 

 crosses the middle of all the wings. This is 

 the true "riband wave." When this band or 

 riband is present there is generally also a 

 waved, narrow, and rather indistinct band 

 between it and the hind margin ; the hind 

 margin itself has a delicate brown line, inter- 

 rupted only by the wing-rays ; the fringes of 

 all the wings are of the same ground colour as 

 the wings themselves, but at the end of each 

 wing-ray is a round brown dot in the fringe. 



The CATERPILLAR is rough, rather like 

 shagreen, being divided transversely into 

 narrow sections of segments, and these being 

 composed of minute warts ; its ground colour 

 is dark brown, except towards the anal ex- 

 tremity, which is ochreous-gray ; on each side 

 in the region of the spiracles is a pale, almost 

 white line : it feeds on a great number of 

 hedgerow plants, as water avens, common 

 avens (Gevm rivals and G. urbanum), meadow 

 sweet (Spir&a ulmaria), &c. 



The MOTH appeai-s about midsummer, and is 

 very common in England, Scotland, and 

 Ireland. (The scientific name is Acidalia 

 aversata.) 



194. The Plain Wave (Acidalia inornata). 



194. THE PLAIN WAVE. The antennae of 

 the male are very slightly pubescent, those of 

 the female quite simple. All the wings are of 

 a pale dingy yellowish gray with a slightly 

 iridescent gloss something like mother-of- 

 pearl ; the fore wings having generally five 

 transverse waved lines, and the hind wings 

 four ; all these are very pale, although darker 

 than the ground colour of the wing : on the 

 fore wings there is a central brown spot on 

 the second line ; on the hind wings there is a 

 similar central spot on or just below the first 

 line ; the hind margin itself has a delicate 



brown line interrupted only at the wing-rays ; 

 the space between the outer transverse line 

 and the hind margin on all the wings is fre- 

 quently intersected by one or two paler 

 waved transverse lines ; the fringe is un- 

 spotted. 



The CATERPILLAR rests in a straight posture, 

 and does not fall off its food when touched or 

 disturbed; the head looks downward, and not 

 forward; the body is rather flattened, and 

 spread out at the sides ; the divisions of the 

 segments are very clearly marked, and each 

 segment is divided by transverse furrows into 

 eight rings ; these rings in the second, third, 

 fourth, ninth, and following segments are 

 composed of warts which emit short stumpy 

 bristles ; the colour is red-brown, with little 

 variation of shade, but having a whitish me- 

 dian spot on the back of the sixth and seventh 

 segments. This caterpillar feeds on several 

 low plants, and also on low shoots of willow ; 

 it is full fed at the end of May ; and then 

 spins a slight web among the leaves of its 

 food plant, and therein changes to a CHRYSALIS. 



The MOTH appears about midsummer : it is 

 not common, but has been taken in several 

 of the English counties, and at Kingstown 

 and Killarney, in Ireland, but not in Scotland. 

 (The scientific name is Acidalia inornata.) 



195. The Portland Riband Wave (Acidalia 



degeneraria) . 



195. THE PORTLAND RIBAND WAVE. 

 Antennae simple in both sexes. Fore wings 

 slightly hooked : all the wings pale yellowish- 

 gray, the fore wings having a reddish costal 

 margin and a broad transverse brown band 

 situated rather before the middle of the winir ; 

 in this band is a central brown spot ; half 

 way between this band and the hind margin 

 are two transverse waved lines very near 

 together, the inner being rather darker than 

 the outer ; the hind margin itself has a 

 delicate dark line: hind wings with the baaal 



