16 THE ENTOMOLOGIST'S RECORD. 



incisions are deeply cut, especially in the dorsal region. The dorsal 

 depression between the ridges is not nearly so marked, and the general 

 impression of this portion of the segment is that of a plane gently 

 inclined towards the posterior margin. The spiracular flange shows a 

 tendency to expand in slight ridges for a short distance upwards along 

 both margains of the segments, leaving a central depression, in which 

 the spiracle is situated. As regards the tubercles, the remarks on the 

 previous instar apply to this stage also. There is only a slight increase 

 of smaller tubercles, and the larger ones are practically the same in 

 number and position. The tubercles on the flange bear long seta?, 

 those on the outer margin being the longest (1mm.), forming thus a 

 fringe around the body. On the 7th abdominal segment, the semi- 

 circular group of tubercles and lenticles has still further increased, the 

 tubercles being almost entirely replaced by lenticles, which number 

 about 30, and are very close together. The centre of the depression 

 is now occupied by a transverse slit, presumably a gland, although I 

 was unable to discover any exudation. The prolegs possess six 

 hooklets in the anterior groups, and four in the posterior one. These 

 are arranged so that half the number of hooklets project beyond the 

 others, forming, as it were, a double row. 



Fifth instar: Length, 9mm., height, 2mm., breadth, 3mm. Owing 

 to the great increase of small hair-bearing tubercles, the larva has a 

 general silky-white appearance, which tends to hide to a large extent 

 the ground colour and markings. The long hair-bearing tubercles are 

 confined to the dorsal bosses, the supraspiracular area and the spiracular 

 flange, on which latter they are especially numerous. On the rear 

 segments, however, with the exception of the flange, these long hairs 

 are absent. The tubercles have now lost all trace of the black apical 

 ring, but are otherwise identical with those of the previous instar, being 

 white cones with spiculated bases, bearing white spiculate hairs. The 

 remaining surface of the body is thickly covered with minute white 

 tubercles, each of which usually carries a small, somewhat atrophied, 

 hair, which is occasionally lacking ; the tubercle has, then, much the 

 appearance of a miniature star-fish, with its circlet of five or six minute 

 spiracles near the apex. The former black lenticles here become very 

 minute, are now of a brownish tinge, and are confined, with the excep- 

 tion of a few irregularly scattered here and there, to the prothorax, the 

 dorsal portion of the 7th abdominal segment, and to the neighbourhood 

 of the spiracles. The spiracles consist of dark brown chitinous rings, 

 with white centres, situated on small white mounds arising out of 

 depressions which, in freshly moulted larvae, appear to occupy the 

 whole breadth of the segment. In full grown specimens, however, the 

 spiracular hollow can be clearly seen to be separated by a ridge from a 

 deeper depression, extending up the posterior portion of the segment 

 from the flange to the second lateral stripe. This depression is deepest 

 at the flange, and, with its rounded margins, gives somewhat the 

 impression of a horseshoe. The spiracles of the 7th and 8th abdo- 

 minal segments are, as usual, very prominent and larger, and the glands 

 of the 8th abdominal are now clearly visible to the naked eye as white 

 spots, situated just posterior to the spiracle. The thoracic plate is in a 

 very deep depression, so that, when the larva is at rest, it is almost 

 hidden by the overlapping mesothoracic segment. The plate itself is 

 white, the anterior margin well rounded, the sides concave, and meet- 



