NOCTUAS. 



237 



quite as attractive as sugar to the night- 

 waudering Noctuas. It has also been found 

 an excellent expedient to sugar isolated 

 thistle-heads when standing up in fields. 

 It is quite useless to offer any of these 

 baits for Noctuas on a bright moonlight 

 night. 



As a general rule, it may be said that the 

 fore wings of Noctuas entirely cover and 

 hide the hind wings when the insect is at 

 rest ; they are never raised over the back as 

 in Butterflies, or rolled round the body as 

 in the Footmen : the ornamentation of the 

 fore wings is very rarely indeed continued 

 on the hind wings, as we so frequently see it 

 more or loss conspicuously in the Geometers ; 

 but it is very uniform, that is, it is gener- 

 ally referable to one pattern, which under- 

 goes almost endless modification for in- 

 stance, near the centre of the wing, in the 

 place occupied by the discoidal spot, which 

 I have described in so many of the 

 Geometers, there are two ocellated or eye- 

 like spots, that is, spots having a different 

 colour in the centre from that on the cir- 

 cumference : the one nearest the body is 

 generally round, or nearly so, and is called 

 the orbicular discoidal spot; the other 

 nearer the tip of the wing, but still not 

 very far distant from the first, is kidney- 

 shaped, and is called the reniform discoidal 

 spot; these two discoidal spots will be 

 frequently mentioned in the descriptions 

 which follow ; the hind wings, besides being 

 less variegated, are generally paler ; never- 

 theless, in some instances, the hind wings 

 are brilliantly yellow, red, or blue, these 

 bright colours being transversely inter- 

 sected with one or two black bands. 



With regard to the position of the 

 Noctuas in a natural system, I am unable 

 to perceive their resemblance to the 

 Geometers, which have always hitherto 

 been placed between Noctuas and the Del- 

 toids. The genus Acronycta unites the 

 Noctuas with the Arctias, and the smaller 

 Noctuas merge so gradually and naturally 

 into the Deltoids that it is utterly impos- 

 sible to tell where one tribe ends and the 

 ocner begins : the series would be not only 

 interrupted, but entirely broken by the 

 intervention of the Geometers, 



412. The Buff -arches (Oonopkora derasa.) 



412. THE BUFF-ARCHES. The antennae 

 are very slightly pubescent in the male, 

 quite simple in the female ; the fore wings 

 are broad and ample, the tip very slightly 

 arched ; their colour is various, and their 

 ornamentation extremely beautiful : an 

 oblique white bar extends from the costa 

 near its base to the anal angle, and this bar 

 emits a branch towards the base of the 

 thorax ; a second white bar extends from 

 the tip of the wing to the anal angle, where 

 it unites with the oblique bar already 

 described ; these two bars unite with the 

 costal margin in forming a triangle, which 

 encloses at least two-thirds of the wing ; 

 the enclosed area is almost white near the 

 costal margin, sienna-brown towards the 

 base, and smoky-brown towards the hind 

 margin ; the whole is exquisitely and deli- 

 cately pencilled ; the basal area of the 

 wing is smoky-brown, and has a semi-trans- 

 parent appearance ; the hind-marginal area 

 is brown, transversely divided into five 

 lines, and these are traversed by a scalloped 

 line of pure white, which is so distinct as 

 to appear like a white thread : the hind 

 wings are smoky-brown ; the head is urnber- 

 brown ; the thorax brown, with its fore and 

 hind margin raised in a ridge or crest ; the 

 body is brown ; the second, third, and 

 fourth segments are dorsally crested. 



The CATERPILLAR rests in a slightly bent 

 position, both extremities being, held clear 

 of its food-plant, and the anal claspers 

 unattached: the head is exserted, and has 

 an almost square outline ; the body is 

 smooth and velvety ; the colour of both 

 head and body is a raw sienna-brown, with 

 a rather paler medio-dorsal stripe : on each 

 side of the fourth segment is a round white 

 spot, and very frequently, but not con- 

 stantly, a smaller white spot on each side of 



