STRYMON PRUNI. 205 



correspond with a similar minute one on the 1st and 2nd abdominal 

 segments, above and in front of the pair. Below the spiracles (lst-7th 

 abdominals) is a group of four hairs, with "thimble "-bases, the hairs 

 similar to i and ii but much shorter, pointing downwards and 

 backwards. The largest of these is rather behind the spiracle, and as 

 much below it as the lenticles are above; just below this (forming with 

 it an equilateral triangle) are two rather smaller, and a still smaller 

 one is level with it, well to the front. Marginally, on the 3rd, 4th, 

 5th, and 6th, abdominal segments, are two very small black tubercles 

 with short hairs. The same pair, apparently, at least at the same 

 level, occurs on all the thoracic segments. On the 1st abdominal segment 

 there is only one rather larger hair centrally ; on the 2nd abdominal is 

 a large lenticle (this lenticle is wanting on the other side), and a small 

 hair below 7 and behind it ; on the 7th abdominal, a lenticle with the 

 hair below T and in front, and, on the 8th abdominal, a large lenticle 

 with the two hairs well below it, looking much like, and in a line with, 

 the others. The group of four subspiracular hairs is represented on the 

 2nd and 3rd thoracic segments, by a pair of rather smaller hairs, nearly 

 level, and above (in line with abdominal spiracle) is a group of three 

 hairs ; these correspond in size with the subspiracular ones, the two 

 lower are a trifle smaller. On the 2nd thoracic is a dark transverse 

 shade between i and ii of either side ; in front of this, on either 

 side, is a single ("thimble "-based) hair directed forwards, with a 

 lenticle just outside it. The 8th, 9th, and 10th abdominal segments 

 present no sutural lines above ; below T the 8th spiracle is a group 

 of six hairs, of w T hich the two posterior probably belong to the 9th 

 abdominal segment, leaving four to correspond with the four here placed 

 on the other segments. Dorsally, the 9th abdominal segment has no 

 armature, i.e., between the tubercle on the 8th and the anal plate is a 

 vacant space, without hairs, lenticles, or anything, which seems a very 

 narrow one. Laterally, below the anal plate, are five hairs continuing 

 the subspiracular range. The anal plate has three longitudinal dark 

 lines, but does not appear to carry any hairs, no long ones like the 

 others at any rate. The prothoracic plate is large, diamond-shaped, 

 stretched out to a point at either side. It has about six very small trans- 

 parent spots on either side, three apparently with hairs. In front of each 

 angle are three hairs in a row T , the inner most forw r ard, tw 7 o similarly 

 en echelon in front of spiracle, with the two marginal ones (already 

 referred to) below. The prolegs have large swollen bases (pedicels), 

 with two fine hairs on their outer sides. There are a pair of hooks to 

 the front, and three to the back, of the inner margin, and between 

 them, and more central, an extensile process, with transparent lappet 

 at end ; the claspers seem to be identical. The head, thoracic plate, 

 anal plate, tubercular bases, rings of lenticles and spiracles, and the 

 abundant skin-points, are black; the true legs are dark, but not black; 

 what seems to be the darker brown of the dorsum is really the effect of 

 the numerous black skin-points (Chapman). Final instar (May 30th, 

 1896) : Colour of a lovely delicate green, with a tinge of yellow in it, 

 especially laterally, the sides ending below in a pale tumid subspiracular 

 ridge. It is w T ell supplied w 7 ith short brown hairs. The ventral surface 

 is much paler — whitish-green rather than yellowish-green ; it is also very 

 glassy, and the skin is more sparingly sprinkled with pale glassy-looking 

 hairs. Read : Very small, exceedingly pale whitish- browm, the mouthparts 



