markings and attitudes of lepidopterons larvfe. 297 



3. Notes upon the adult larva of Smerinthus populi. 

 — The anterior spiracle is hidden when the larva is at rest, 

 as in S. ocdIatKs, and it is also less conspicuous when 

 exposed. There is hardly any ground colour in the 

 oblique stripes, except the 1st and 7th, and only a fair 

 amount in the upper part of the 7th (extending ante- 

 riorly through the 7th abdominal segment). There is 

 just a trace of the subdorsal anteriorly, but it is barely 

 visible, and only consists of dots. The 7th stripe is 

 continued anteriorly and inferiorly on to the 6th abdo- 

 minal segment by a line of dots. So also similar lines 

 of dots are seen upon the 3rd, 4th, and 5th abdominal 

 segments, but they are not as continuous with the 

 oblique stripes behind them as in the former instance. 

 In all cases they are less oblique than the normal 

 stripes, and they have the appearance of a subspiracular 

 line which has been diverted upon each segment into 

 approximate parallelism with the oblique lines. There 

 is the usual annulatiou of the segments. I could not 

 feel sure about the existence of apical tubercles on the 

 head during previous stages. There is no 8th stripe. 

 The shagreen dots terminate in the usual (simple) hairs. 

 These observations were made upon two larvffi in the 

 last stage found upon two species of Salix. Both larvae 

 were yellowish green. 



4. Notes upon an adult larva of Smerinthus tili.e. — 

 The ontogeny of this species is described by Weismann, but 

 it was important for me to examine the larva, especially 

 concerning the question of the origin and structure of 

 shagreen dots. An adult larva was found at Oxford, 

 August 13th, 1884. There was no trace of an 8th 

 stripe or of the subdorsal. The shagreen dots are not 

 nearly so rough as those of S. occllatus or popnli, and 

 yet they terminate in hairs in nearly all cases. The 

 hairs are short and bristle-like, with simple ends. The 

 curious and brightly-coloured plate above the anus is 

 simply composed of large coalesced tubercles still 

 retaining their hairs. The horn is covered with hair- 

 bearing tubercles. The yellow stripes have rather dark 

 anterior margins formed by a deepening of the ground 

 colour. There are two blunt apical tubercles on the 

 head, of a rather darker orange than the band round the 

 face, which has now spread into the ground colour, 

 although the scattered hairs upon it show its origin in 



TRANS. KNT. SOC. T/OND. 18H.5. PAKT II. (aUG.) X 



