122 BRITISH BUTTERFLIES. 



hairs not quite in a line (longitudinally), the larger (0-1 4mm.) middle one 

 being a little lower than the others ; then two marginal hairs (posterior 

 longer, about 0-06mm.), and two minute hairs at base of prolegs. 

 From this, the 1st abdominal diners in having a lenticle in place of 

 the anterior subspiracular hair, and only one marginal hair. In 

 another specimen the subspiracular lenticle does not displace a hair, all 

 three hairs being present. Frequently a lenticle replaces one of the 

 marginal hairs on the 2nd abdominal segment, which has usually no 

 other spiracular lenticle. In the specimen photographed, the irregu- 

 larity of these lenticles is illustrated, the second abdominal having a 

 subspiracular lenticle as in the 1st abdominal, on one side, but on the 

 other it replaces one of the marginal hairs. The 3rd, 4th, 5th, and 

 6th abdominal segments are as described. On the 7th, tubercle ii is 

 replaced by a lenticle (or rather, perhaps, ii is absent, and the lenticle 

 pushed up); there is only one supraspiracular hair w 7 ith a lenticle 

 (second lenticle or two supraspiracular hairs?) just behind it, and only 

 two subspiracular hairs. On the 8th abdominal segment there is, above 

 spiracles on each side, only a conjoined plate carrying i and a large lenticle; 

 the hairs on i, on the 7th and 8th abdominal segments, and the marginal 

 ones behind, are very long, nearly 0'23mm. On the 10th abdominal 

 segment is a small square (anal) plate (about O05mm. across) without 

 hair or lenticle. The hairs round the posterior margin cannot be 

 definitely assigned to the 8th, 9th, or 10th abdominal segments ; 

 there are, on each side, two long ones posteriorly, and one further out 

 (probably on the 10th segment) and a further one (probably on the 9th 

 segment), with seven short hairs ; below the margin the short hairs belong- 

 apparently to the base of the claspers. The prolegs and claspers consist 

 of an anterior and posterior set of hooks, each consisting of one larger 

 and one minute hook, the latter not infrequently missing. The true 

 legs have the usual three joints, the first short and broad, the last long 

 and narrow, with a well-curved hook. The hairs are very finely 

 spiculated, so finely that, without considerable magnification, one takes 

 them to be smooth ; their bases are simple cones. The general surface 

 is covered by fine skin-points, more pronounced over the middle of the 

 segment than towards the incisions ; near the latter they seem (in a 

 mounted skin) to be mere points, but, near the summit of the segments, 

 they have a polygonal aspect, not quite square, and with angular irregu- 

 larities. They are about 0-0015mm. in diameter, and a similar 

 distance from each other, varying with the degree to which the skin is 

 stretched, irregularly placed, but often here and there in rows running 

 nearly longitudinally or transversely ; so far as a count is possible, 

 about twenty points from back to front of a segment. Second instar : 

 In the second instar the larva reaches 3mm. when fully stretched, the 

 black head is , 42mm. wide, a greater growth from the first instar than it 

 makes at the next two changes. There is a considerable increase in the 

 number of hairs, but lenticles have nearly disappeared from the dorsum, 

 but have increased in number, although not proportionally in size, in the 

 spiracular region. The hairs are actually longer, but proportionally 

 shorter, i on the abdomen being about 0*2mm. in length. Taking the 2nd 

 abdominal as a sample, we find on each side i and ii much as in the first 

 instar. In front of them are two shorter hairs, one nearly in front of 

 the other ; betw r een them and the spiracle are seven short hairs (about 

 0*06mm. or 0*07mm. long). There are no dorsal lenticles, but three 



