COCHLIDION AVELLANA. 373 



of a similar large, open, circular shape as the structure we have sup- 

 posed to be the prothoracic spiracle, but the rim is only of a darker 

 shade of green than the ground colour, and the central area is greenish- 

 yellow. They are placed somewhat more than halfway up the lateral 

 area of the larva. There is a single, pale, subspiracular hair on each 

 segment, and one longer hair on either side of the dorsum of the anal 

 flap ; several others are to be found on the posterior portion of the 

 anal segment. Chapman has also noted that these hairs are 

 present in the 2nd, 3rd and 4th skins, and we draw special attention 

 thereto, as Dyar suggests (ante, p. 364) the general absence of sub- 

 spiracular tubercles, which these undoubtedly represent. The true legs 

 are well-developed, transparent, green in colour, with a pale brown 

 hook. [Described from Westerham larva, October, 1897.] 



Larval spines. — The development of the spines of this larva is 

 very remarkable. At the time that the larva has completed its growth 

 in the eggshell, it is without any spines or processes, but at the period 

 of hatching certain long spines, of which there are at least four on each 

 abdominal segment, are rapidly developed, and are arranged as a dorsal 

 and lateral series on either side. The ordinary tubercles can be 

 detected as faint dots, but these spines are quite independent of the 

 ordinary tubercles, and differently placed. Chapman says that the 

 dorsal series on one side, although consisting of one spine only 

 on each segment, has them placed as though they were the double 

 rows of Eriocephala (i.e., Micropteryx, ante, p. 138), with alternate 

 spines omitted, i.e., the inner spine is wanting on the 1st abdominal 

 segment, the outer one on the second, and so on, alternately. 

 Dyar considers the alternation as a sign of weak and strong segments). 

 Laterally, the spines appear to belong to the lower row of the lateral 

 series of Eriocephala (Micropteryx), but the upper row is represented 

 on the thorax by two spines. With regard to the growth of these 

 spines, a circular mark is seen in the unhatched larva, on the site of 

 each spine, and is the summit of a cylindrical body deeply embedded 

 in the larval substance. This body is, in fact, the spine, of which the 

 upper third appears to be already, stiff and solid, with its apex on the 

 surface ready to emerge, whilst the lower two-thirds form a soft in- 

 vaginated sheath surrounding the upper part. When half of the soft 

 portion of the spine has emerged, there appears upon it a spur, and, 

 when the emergence is completed, a distinct joint is visible at the base 

 of the upper portion. The soft portion appears very rapidly to become 

 hard. These spines are about equal in length to the diameter of the 

 larva, and are divisible into three portions : (1) The basal, rather thick 

 and smooth, and terminating at the lateral spur. (2) The middle 

 portion, continuous with the basal and structurally the same — only 

 narrower — and quite smooth. (3) The terminal portion, separated 

 from the middle portion by a joint, or transverse line of union, with a 

 series of minute points or teeth, apparently arranged in a somewhat 

 spiral manner along its shaft, and terminating at the apex in a slight 

 enlargement, and a coronet of angular points, six to nine in number. 

 The lateral points are difficult to see except when taken in profile, but 

 are rather numerous and laterally arranged. The inner structure of 

 these spines has all the appearance of consisting of a separate included 

 tube running its whole length, and having a branch to the lateral spur. 

 After the first moult, these spines are replaced by straight spines, 



