42 tJ"iy' 



On the Natural History and position of Aventia flexula. — It is not often that 

 I have taken on myself to make any remarks on the position of a species in any of 

 the Lists which from time to time are put forward, but in this case I cannot help 

 saying a few words. 



It certainly seems that the imago has been a puzzle to systematists, for we find 

 its position varied from one division to another repeatedly ; but I think that a 

 knowledge of the larva state would have prevented all this uncertainty. 



Staiidinger to ray mind has come nearest the truth, in placing Aventia at the 

 end of the Noctuce — among Catocala, Toxocampa, &c. ; but I think he is wrong in 

 letting Toxocampa come between Catocala and Aventia. And in my description 

 below, I shall italicise those points in the larva of Aventia which induce me to 

 place it next to Catocala. 



The full-grown larva is seven-eighths of an inch in length, widest at the ninth 

 and tenth segments, the head full but rather less in bulk than the second segmeat ; 

 the anal flap rounded ; the body above is convex, but each segment a little sivollen in 

 the middle and scored across with two deep wrinkles, both at its hinder end ; beloto 

 the spiracles is a rather inflated projecting ridge, fringed with a row of fleshy 

 filaments ; some of these filaments are simple, others are branched like the ' chevaux 

 de frise ' one sees sometimes on enclosure walls ; the belly is flat ; the anterior legs 

 well developed ; the first two pairs of ventral legs much shorter than the other two 

 pairs, though each pair is progressively longer than the preceding, the anal pair 

 being the longest ,- the dorsal tubercular warts are prominent, each furnished with a 

 fine short hair; on each segment the hinder pair is much larger than the front pair, 

 and on the ninth and twelfth segments largest ; on the twelfth they are placed on a 

 transverse prominent ridge. 



The colour is of a more or less pale, dull, bluish or greyish-green, or else this 

 colour slightly tinged with brownisli-ochrcous, rather paler on the sides ; the dorsal 

 line darker green, being in fact a series of spear points faintly edged with whitish- 

 green, and by short black, streaks at the end of each segment ; the sub-dorsal marking 

 is a paler tint of the ground, to be seen plainly only just at the segmental divisions, 

 but its course is indicated well enough on the other parts by- a fine sinuous line of 

 black above, and a line of darker green below ; the ninth and twelfth segments are 

 darker in tint than the others ; slight curves of blackish dots or dashes are on the 

 back of the second, third, and fourth segments along the sub-dorsal region ; the head 

 is more whitish-green than the body, and is marked with sjjots and curves of black 

 on each lobe, and about the mouth ; the tips of the tubercular warts are black, on 

 bases of whitish-green, and a broad streak of tliis pale colour is on the side of each 

 segment beyond the fourth ; tlie filaments are greenish-white ; the belly a dull, pale, 

 bluish-green ; the anterior legs are spotted with black, a black streak runs down the 

 front of the fourth pair of ventral legs ; the spiracles of the ground colour ringed 

 with dark brown. 



The habit of the larva is to lie close by day for hours together, with its legs 

 spread out flat to their full extent upon lichens, on which at night it feeds. 



I am indebted to several friends for opportunities of studying this species. Mr. 

 Harwood sent me in 1868 the first I ever saw, which he had beaten either from oak 

 or aspen, and then I took it to be a young Catocala. The Rev. B. Smith and Mr. 

 W. Machin kindly sent me others beaten from lichen-covered thorns, cherry and 



