CELASTRINA ARGIOLUS. 436 



bare of hairs, but an actual gland is not verified. The glands of the 

 8th abdominal are not detected. The abundant secondary hairs are 

 about 06mm. long, longer in some cases when they approach i and ii 

 or iv and v ; they are very delicate, somewhat curved and clubbed, i.e., 

 narrowest at origin, and with some trace of the curious hacked scimitar 

 form so marked in next instar (pi. xxvi., fig. 1); their bases have five or 

 six long stellate processes, not spikes, standing out at an angle (approxi- 

 mately) of 45°, as on the bases of the primary hairs, but long (OOlmm. to 

 O02mm.), with rounded ends, and horizontal, i.e., parallel with the skin- 

 surface below ; the lenticles nearly all have lateral spikes, more or less 

 intermediate, but more like those of the primary hairs than like those 

 of the secondaries, and decidedly smaller ; all the hairs are markedly 

 spiculated. The prolegs have each two (anterior and posterior) pads 

 each with four hooks. The hooks on the claspers are a little larger, 

 but the posterior pad has only three hooks. When ready for the second 

 moult (June 4th, 1907), two larvae were 3"5mm. long, green in colour, 

 slightly modified by numerous black dots on slopes, and paler colour 

 of dorsal region, which is without dots, and has longish white hairs. 

 The larva is broad and, especially, high; the dorsal ridges are rounded, 

 but make a considerable approach to the form of the larva of Ruralis 

 betulae, especially in the ridges separating on the thorax, so as to 

 include a forward plane or slope ; the lateral line is pale, hardly 

 yellow, and there is some indication of lighter and darker green 

 marking the oblique lines ; the dark dots are small tubercles, those 

 dorsally are larger and paler, but of quite the same structure ; on one 

 segment 30 are counted from the dorsal line to the spiracle on one 

 side, and this distribution seems to be exceedingly uniform over the 

 whole larva ; the structure of these tubercles is remarkable ; they 

 consist of a short, thick, rough, almost clubbed, hair # 06mm. long, 

 bent backwards (tailwards) so as to lie parallel to the surface ; their 

 base is expanded into a barrel-shaped piece, from the sides of which 

 project, like the spokes of a wheel, six or seven fine hairs, perhaps 

 about 0-02mm. long, occasionally with one rather longer and stronger, 

 not unlike the warts on certain plumes, e.g., Ovendenia septodactyla. 

 The approach of the larva to typical (by typical, meaning rather fully 

 elaborated) Lycaenid form, as in Ruralis betulae, combined with this 

 curious armature, is striking. Third instar (June 5th) : Two larvae 

 just moulted, and eaten their cast skins, are green, with black heads, 

 and so densely felted with hairs that no details of them can be made 

 out, but they appear to be of the same character as in previous skin. 

 By June 10th the larvae were laid up for the third moult, therefore, 

 fullgrown in third stadium. The larva is very like its appearance in 

 previous instar, except that it has a light red-brown dorsal band, 

 broadest in front, and a reddish lateral line, and that the spiculate (white) 

 hairs are more numerous. Along the dorsal ridges there are, on each 

 segment, longer hairs, two about - 35mm., two a little shorter, and, on 

 each side, altogether, nearly twelve, more or less longer than the general 

 surface hairs, which are about 0'08mm. long ; these large dorsal hairs 

 have naturally much larger basal cones than the others, the cones 

 possess, also, the side-spicules, but the latter are not only propor- 

 tionally, but are actually, shorter than on the smaller bases. There 

 are, on abdominal segments, 70 to 80 hairs on one side from dorsum 

 to level of spiracle. The skin-surface presents a fine network or 



