180 BRITISH LEPIDOPTERA. 



the subdorsal sloping upwards at head and caudal horn (as in Sesia 

 stellataruni), Drighter yellow patches on the subdorsal band are now 

 visible, situated on the enlarged ist subsegment of the meso- and meta- 

 thorax, as well as on abdominal segments 1-8. This enlarged ist subseg- 

 ment is clearly in some (and probably in all) cases, composed of 

 three subsegments, thus making up the normal number of 8 found in 

 Sphingid larvae. The primitive setae are still distinguishable owing to 

 their larger size. Third instar (August 6th, 1901 — described with 

 hand-lens only): No. 1. The larva somewhat of the shape of that of 

 S. stellatarum ; neat and compact without being either long or stumpy ; 

 the caudal horn small, but well-developed, dark purple (almost black) 

 for the upper four-fifths of its length, covered with numerous thorny- 

 looking hairs. The head more rounded than in last instar and 

 covered with many fine dark bristles or short stout hairs. The scutellar 

 plate is conspicuous, being coloured similarly to the head and unlike 

 the body; the subdorsal bands do not reach it, the hairs on it are 

 numerous, and agree with those on the head in colour and in the 

 fact that there are no coloured shagreen-spots at their bases. The 

 spiracles are white, edged with a purple-black chitinous rim, the 

 larger size of those on the prothorax and 7th and 8th abdominals 

 is still noticeable but not so marked as in earlier instars. The 

 subsegments are really 8 (or even 9 if an obscure fold in the skin 

 at the junction of the segments be counted) in number * ; the first 

 three are, however, poorly subdivided and form the large ist sub- 

 segment, giving really 5 (or 6) small and 1 large subsegment. The 

 shagreen-spots at bases of hairs are conspicuous, but on the enlarged 

 ist subsegment they have a tendency to weakness, especially on the 

 dorsal area ; they are also inconspicuous behind the caudal horn; 

 these basal shagreen-spots are absent on the stripes, doubtless because 

 the stripes were originally developed from the spreading of the 

 coloration at the base of the hairs. There is a broad, well-developed, 

 subdorsal, cream-coloured band which, near the horn, is bordered 

 above by a darker margin ; on the subdorsal band are a series of 

 bright yellow spots, which occur where the band crosses the ist 

 (enlarged) subsegment of each segment from the mesothorax to the 

 8th abdominal, inclusive ; these spots are oval rather than round and 

 slightly broader than the band on which they are situated ; they are 

 bordered above by a narrow dark line. There is also a broad, well- 

 marked, infraspiracular band of pale yellow or cream-colour with a 

 tendency to develop a bright yellow spot just beneath each spiracle, the 

 spot surrounds tubercle iv, the only primitive seta that is now distin- 

 guishable (with a handlens) from the shagreen tubercles. The true 

 legs are pale green. The larva just described in 3rd instar is of a pale 

 bright green tint, slightly darker on dorsal area, and with a bright 

 yellow-green dorsal stripe ; the head, scutellum and anus being 

 of a paler and more pellucid green. [This is called No. 1 in the 

 following notes. Two other forms are now described in the 3rd 

 instar as Nos. 2 and 3.] No. 2 in third instar. — The head dark 

 dusky green, datk olive (almost black) at crown and round the mouth- 

 * Each segment of the body, except the thoracic and posterior segments, 

 lias a very broad subdivision in front on the back, followed by six narrow ones, 

 though, whilst the larva is very young, the two hinder folds are united into a broader 

 one, the last wrinkle being smoothed out ; these wrinkles or folds extend as low as 

 the spiracles (Buckler). 



