BITHYS QUERCUS. 247 



brane [?] or present partially [?] in Hepialids). Of these may be 

 noted — on the front margin of segment, one outside ii, one above the two 

 (true) marginal hairs on thorax, below on abdomen ; in front of the 

 prolegs, just short of the front margin, possibly representing ventral 

 hairs of other abdominal segments. There are certain ventral and anal 

 areas where the skin-points are quite spicular. Second instar: The larva 

 in this stage has almost identical colour and markings with those of 

 the large first stage larva, the anal plate is nearly as dark, but the pro- 

 thoracic plate, though well marked, is marbled dark and light, much 

 like the general surface. Head black. Length nearly 4mm. Hairs 

 more numerous, but still a dorsal and lateral crest, with a few short hairs 

 on slope ; the crest hairs are pale and seem to be not actually larger than 

 those of larva in the first stage. Same instar (laid up for moult April 17th): 

 Length 6mm. Oblique lines very marked, with darker shades on each 

 side of them. Widening of dorsal groove (or plain) on thorax also 

 marked. The prothoracic plate brown, with some short hairs, and 

 surrounded behind by a white, smooth area, which is probably not 

 part of the plate. In the second instar, the hairs are much more 

 numerous, a dorsal and lateral set still predominant, but they exist 

 over the whole larva, irregularly disposed. Lenticles are comparatively 

 scarce ; one is tempted at first to say wanting. Perhaps the most 

 notable difference is the absence of the black skin-points, so conspicu- 

 ous in the first instar ; the skin is now transparent, and set out on a 

 pavement-epithelium pattern ; on the ventral aspect there are 

 spicular skin-points, hardly tinted however. The prothoracic plate is 

 06mm. across, more angular on its front margin, but otherwise of 

 similar shape ; there are fifteen or sixteen hairs on each side, the 

 longest about 03mm. long, and one not very conspicuous lenticle. In 

 front of, and above, the spiracles, on each side, are about 30 hairs ; on the 

 spiculate surface in front of prolegs? (below "chin") are some curious, 

 little, broad, pointed, javelin-like hairs (O025mm. long) ; amongst 

 these is one lenticle, and another in front of spiracle. On the dorsal 

 area of the 2nd thoracic are two lenticles, one in the lateral, and one 

 in the marginal, region ; they are nearly lost amongst the numerous 

 hairs present in all these regions. Down the dorsum, lenticles are 

 given to be present, two on one side, and only one on the other. The 

 longest hairs are 0-4mm. to 0'6mm. long. The two pads of the prolegs 

 have five or six hooks, and the outer upper set have 5 to 7 also, and 

 much like the others in size ; they are, however, of equal length ; the 

 other sets (pad) tend to have alternate lengths ; the longest are about 

 0*03mm. long. On the abdomen are two lenticles (sometimes three) 

 near the spiracle ; there are about 70-100 hairs to a segment, still a 

 little grouped by size, and slightly by distribution to the dorsal, lateral, 

 and marginal areas ; the longest about - 5mm., except on the 8th and 

 9th abdominal segments, where are several 0-6mm. long; the margins of 

 their bases are more crenate, and tend to divide in the petaloid 

 manner. Third instar (April 21st) : (1) The larva is 8mm. long, and 

 is not yet much grown in this instar ; pale nut-brown, w T ith pale 

 dorsal (subdorsal ridge), lateral and oblique lines ; the latter start 

 at front of segment almost with subdorsal lines, and run down 

 and back, meeting the posterior margin of the segment, or rather not 

 quite reaching it ; halfway between the subdorsal and lateral lines it 

 is margined below with a much darker shade, giving the triangle 



