350 LÉPIDOPTÉROLOGIE COMPARÉE 



white bars, also, are to be seen at the base of each leg. Before the 

 anal plate, in Lycia and Pœcilopsis, there are two white spots, but 

 their absence, in Ithysia, is compensated by the early development, 

 both dorsally and ventrally, of longitudinal stripes. 



Of course, it is to be understood, that there are certain différences 

 of spécifie value in the larva^ of each species. 



The larva in its last instar, is more or less cylindrical, varying 

 in this res^iect with the genus as do one or two other structural 

 points which will be emphasised later. Attention is now drawn 

 to the scheme of markings, v/hich is common to the adult larvae 

 in the group. The ground colour of ail may be of a grey tint, 

 but in rachelœ, hirtarïa and lapponaria it is usually purple; in 

 pornoîiaria a cream of somewhat grey shade, and in the others, 

 a grey tending more or less to yellowish green. The head is grey 

 or purple, strongly black spotted. The dorsal area is provided 

 with six more or less broken longitudinal stripes, outlined with a 

 black edging, which is generally continuous in Lycia and Pœci- 

 lopsis, but broken and irregular in Ithysia. On abdominal 

 segments i, 2, 3, 4, 5 in the former gênera, the original transverse 

 bars persist and are well marked to the end, but in Ithysia, 

 they become obsolète early. A similar state of affairs holds 

 with the collar. Before the well marked anal plate there are two 

 yellow spots in Pœcilopsis and Lycia, preccded on segment 8, by 

 two large warts; both the warts and yellow spots fail in Ithysia. 

 There is a spiracular stripe, weakly developed in ail exccpt 

 Ithysia, in which it becomes sometimes very broad and strong. 

 In the others, hov/ever, the large yellow spots along the spiracular 

 line are very large and prominent. Before and after the yellow 

 transverse bars, and before the yellow spiracular spot, there may 

 appear strong black shadings in Pœcilopsis and Lycia. 



Ventrally, we may hâve four or even six longitudinal stripes, 

 similar to those on the dorsum. The legs and prolegs are gene- 

 rally like the ground in colour but they possess obscurely paler 

 markings. The plates on the prolegs and the anal plate are 

 slightly darker than the ground colour and are heaviiy speckled 



