T. BISTORTATA, T. BIUNDULARIA, AND ITS VAR. DELAMERENSIS. 245 



The fourth utai/c is characterised by degradation of most of the 

 mai'kings, except the supra-spiracular lines, the commencement of the 

 dorsal line and the edging of the humps ; a general lowering of the 

 tints with accompanying definition of tubercles i and ii (anterior and 

 posterior trapezoidals), especially ii, and spiracles ; and a glossy 

 appearance assumed when full-fed on the eve of pupation. 



The dfscrij)f,ion of thr fuJl-fed larra is as follows — Length, 3'65 to 

 4 cm. (1" 5'" tol"7"'). It is slightly swollen transversely on the 

 meso-thoracic segment, smooth and glossy. The ground colour 

 varies from that of putty to pale yellowish or reddish-brown, with 

 darker maculations. The dorsal stripe is edged with black or grey, 

 swollen in the centre of each segment, and suffused with grey, or 

 sometimes broken, but in all there is a linear longitudinal velvety 

 black mark at the edges on the front of the meso-thorax, extending 

 partly on to the pro-thorax. The supra-spiracular stripe is conspicuous 

 with black edgings, in many filled up with black or dark grey, 

 especially on the hind part of the thorax and abdl. segts. 1, 2. It has 

 a transverse velvety intense black marking on the front of the meso- 

 thorax. It is fainter posteriorly, often broken before abdl. segt. 2, and 

 continuous with the dark marks on the side of the hump on segt. 8. 

 There is a more or less distinct dull black V-shaped marking, 

 pointing forwards, often edged in front with orange or red spots, on 

 segt. 2 (sometimes very indistinct or absent). A similar marking is 

 frequently traceable on segts. 3, 4. Segts. 3,4,5 are more or less 

 sufiused with black, the amount varying much. The dorsum is 

 conspicuously paler on segts. 6-9. Tubercles ii (posterior trapezoidals) 

 are very distinct on abdl. segts. 2, 3, 4, 5, each with a degraded hair ; the 

 other tubercles can also be traced. The reddish pimples on the 

 humps of segt. 8 are seen to correspond with tubercles i (anterior 

 trapezoidals), moved a little further back. The spiracular line is 

 broad pale yellowish-white, more or less mottled with brown, very 

 conspicuous on segt. 6, where it passes down in front of the base of the 

 proleg, and somewhat less so on segts. 2, 3, 4, 5. It is darkest 

 towards the front. The spiracles are oval, edged with dark brown, 

 conspicuous, and those of the abdominal segments placed about the 

 centre of the line. The undersurface, as far as abdl. segt. 6, is coloured 

 like the upper, but darker, and often sufiused with a great deal of 

 black, either partially or entirely ; there are some paler central 

 lines. It is very pale on segts. 7, 8, 9, where colour is not required 

 for protective purposes. The legs are darker than the pro-legs, which 

 are of a reddish-brown colour. The head is a little smaller than the 

 next segment, and obliquely truncated. It is pale yellowish or reddish- 

 brown, mottled with darker spots or streaks, some forming a more or 

 less distinct W on the upper part of the face, the inner lines of which 

 are often very dark and conspicuous. 



I'he second brood of T. bistortata. — I have to thank Mr. Bacot for 

 ova of a captive Clevedon 2 , laid about the end of June, They 

 hatched on July 7th, and the larvae pupated between July 30th and 

 Aug. 5th, a period of 23 to 29 days. The ova are similar to those of 

 the 1st brood, but smaller. The average length of the long axis is 

 •726 mm., of the short axis "5 mm. A description of the larva 

 corresponds in all its stages with that of the 1st brood ; but, taken as 

 8, whole, this brogd -vyas darker, the markings more defined and 



