NOTES TOWARDS A LIFE-HISTORY OF THESTOR BALLUS. 279 



indeed, they look as if they probably meet behind the pad, are two 

 similarly shaped pads armed with crochets. The fullfed larva stretched 

 out is 20mm., or even a little more (21mm. -22mm.). The general colora- 

 tion is now a dark violet-purple, made up, however, of several distinct 

 elements. The dorsal humps are still yellow, but they have not grown 

 with the larva, and are now rather small warts on the middle of the 

 dorsum of each segment, but, narrow from side to side ; they tend to 

 have a ridge running from each to the next, whilst the rest of the 

 yellow colour at and beyond their bases is now modified towards violet. 

 The marginal flange is also less yellow, and even pale and colourless 

 at the forward segment. The dorsal line is still deep chocolate-red, 

 but it spreads opposite the humps, invading them a little, and the rest 

 of the dorsal area within the humps is pale transparent, with a central 

 broad chocolate dash, giving a violet or lilac effect. The subspiracular 

 flange stands out very prominently on each segment, almost as a (very 

 rounded) point, so that the "slope" is still marked. The oblique 

 stripe is very dark chocolate, with pale, hardly yellow, above and 

 below. There is a very broad red-chocolate area below the spiracles, 

 and the prominence of the subspiracular flange makes this area very 

 flat (facing dorsally), and therefore very conspicuous. The black 

 spiracles, in a narrow pale ring, are also very conspicuous. The pale 

 area below the oblique stripe is still a little yellowish, and is divided 

 into two portions by a dark shade going down behind the spiracle, and 

 the lower margin in front is a little oblique, so that a casual view gives 

 the whole " slope " as having alternate pale and dark oblique stripes. 

 The 2nd thoracic segment is largely invaded by a rich vinous-red, 

 which also occurs on the 1st, and also on the later, abdominal segments. 

 The dorsal area of the 7th, 8th, and 9th abdominal segments has a 

 curious effect, looking and being flat, in comparison with the high and 

 angled segments in front. The 7th and 8th are really narrower than 

 the 6th, but look broader, owing to the sudden narrowing to the 9th. The 

 subspiracular flanges (or humps) are rather fuller and thicker than on 

 segments in front, and are a little more dorsal, and they have a 

 peculiar aspect from being apparently welded together into one 

 double piotuberance ; the 9th is rather square, i.e., it has two 

 rather parallel sides and a square end. The prominences (subspira- 

 cular) of the 7th and 8th are red, of the 9th yellowish-reddish, and with 

 a muddy overlaid transparency. The four black spiracles are con- 

 spicuous black spots, and the end still has something of the look of the 

 back of a crocodile head. The dorsal coloration of the segment is a 

 chocolate-red, with a somewhat darker dorsal line. On the 7th, the yellow 

 of the dorsal prominence of the previous segments is represented by a 

 short whitish oblique band, or stripe, on each side of the dorsum, stop- 

 ping before the posterior margin of the segment, and with their ends 

 joined by a transverse pale band. In the centre of this band is a trans- 

 verse depressed line, looking like the opening of an eversible gland, 

 of which I have not, however, seen anything more. Behind each 

 posterior spiracle is a pale spot, and once, in the full-grown larva, I saw 

 everted a white cylindrical tube with a domed summit, about 0-5mm. 

 high, and 0-25mm. across, and with a finely spiculated surface. This 

 description is rather the impression left by a short examination through 

 a lens, though an actual description. The prothoracic plate has a width 

 of less than -| that of the segment, its outer angles sharp, the front 



