208 BBITISH LEPIDOPTEEA. 



segments are well enclosed in chitinous plates of the same texture as 

 those forming the dorsal plate of the prothorax in so many lepidop- 

 terous (and other) larvae. There is a gradual transition in paleness, 

 from the pro- to meso-, and meso- to metathorax, but an abrupt break 

 to the very pale, white or straAV-yellow, abdominal segments, the colour 

 being due to contained fat-masses, the skin itself being colourless, as 

 well as in the size, the thoracic segments being swollen for leg-attach- 

 ment. Except for the usual four pairs of ventral prolegs on 3-6, the 

 abdominal segments are much alike, the 9th is similar but very narrow, 

 the 10th large and swollen, carries a strong dorsal plate and two 

 powerful prolegs. The abdominal segments are flattened beneath ; 

 the thoracic being nearly cylindrical, look, by comparison, rounded 

 beneath. The larva viewed laterally has much resemblance to many 

 coleopterous larvae owing to the strong legs and the swelling of the last 

 segment. This is probably accentuated by the shrinking already 

 referred to. The abdominal segments consist of certain plates, 

 apparently firmer than the general integument, though differing but 

 slightly in colour, having a trace of fuscous, and not obviously different 

 in texture, but they are separated by furrows. The plates are more 

 shiny and polished than the general surface. These plates are : (1) A 

 broad plate on either side dorsally at the front of each segment, broad 

 at the median line, diminishing to an angle outwardly. (2) Posterior 

 to 1, on either side, a plate obliquely placed, broad at the outer end, 

 narrowing to the middle line and larger than the anterior plates, 

 although less markedly so on the hinder segments. [These plates pro- 

 bably represent trapezoidal tubercles, not altogether unlike those of a 

 newly-hatched Acronyctid larva, e.g., Jocheaera alni.] (3) A triangular 

 plate below 1 and 2, and forming the lateral flange, Avith its base 

 forwards, the series, viewed dorsally, presenting a serrated outline. 

 (4) Two narrow plates, below 3, which, viewed together, form two 

 longitudinal cylindrical ridges. (5) Similar to 4 but quite ventral, 

 broadened posteriorly and tending to meet its fellow on the opposite 

 side in the middle line, by leaving a space in front, which, in the seg- 

 ments without prolegs, is occupied by (6) an oval plate, occupying the 

 middle line and common to both sides. Each of the two dorsal plates 

 carries a short bristle, the posterior being the larger, viz., about ^th 

 and i-th the diameter of the larva in length, respectively, the posterior 

 being longest on the posterior segments ; these are i and ii, and are 

 arranged trapezoidally, ii being slightly external to i ; iii is also present as 

 a supraspiracular tubercle. The first (anterior) cylindrical plate carries 

 a minute bristle at its anterior end, and the second (posterior) two 

 bristles, a larger and a smaller, the latter in front about its middle ; 

 on the ventral plate are also two on either side, at the bases of prolegs 

 on 3, 4, 5, and 6 abdominals. The prolegs have no very distinct 

 pedicel, and bear an elliptical series of hooks, broken, however, at the 

 inner edge, and on contraction forming an anterior and posterior row, 

 the hooks are, especially in the posterior row, smaller towards the 

 median line. The hooks are 16-18 in number, eight or nine in each 

 row, the number variable, most numerous on the 3rd pair of prolegs, 

 which sometimes have 20. The anal hooks are precisely similar, 

 17-19 in number, rather larger, the ellipse rather more circular, with 

 a rather larger gap in the hooks at its inner edge ; tbe individual 

 hooks are short and thick, but, especially in the anal ones, have a very 



