THE GENUS ACRONYCTA AND ITS ALLIES. 77 



one, as also the posterior spiracular tubercles, which are 

 dwindling, the subspiracular and marginal tubercles are longi- 

 tudinally linear ; the paleness of the pale segments especialh- 

 appears as a white area around the posterior trapezoidal 

 tubercles, and as the larva becomes full grown (in this skin), 

 the paleness of these segments looks no longer a weakness or 

 defect, but takes the form of a bright yellow area around the 

 posterior trapezoidals. All the tubercles appear to have a pale 

 line round them ; this is most marked in the subspiracular, 

 where the paleness on their upper margins forms a pale lateral 

 line, apparently continuous across the dorsum of the 13th 

 segment, where the paleness is whitish instead of yellow, as 

 noted above in regard to the other pale segments. 



In the third skin the larva is again black at first, from close 

 setting of the tubercles ; its length is 5 to g mm. The pos- 

 terior spiracular is now a mere dot, but the other tubercles are 

 large, the anterior trapezoidal the largest, with twelve hairs. 

 The posterior trapezoidal and subspiracular tubercles now 

 have a few shorter pale hairs in addition to the longer black 

 ones. The 5th and 12th segments are still much the largest, 

 perhaps hardly to be called humped, and the nth is still 

 weaker than its place in the series requires. The colour of the 

 skin is a light rufous brown, the pale segments 3.4, 6.7, 10. 

 II, have a brilliant yellow area below the anterior trapezoidals, 

 and reaching down to half-way between the posterior trape- 

 zoidal and the supra-spiracular tubercles. (On 3 and 4 it 

 reaches the tubercles that appear to correspond with these.) 

 A pale whitish area surrounds the black spiracles, the yellow 

 marking crosses the back of 13, and is continuous with a 

 lateral line above the subspiracular tubercle as in previous 

 skin, and yellow markings exist anteriorly and posteriorly on 

 the dorsum of the 12th segment. 



In the fourth skin (length g to 15 mm.) the larvae are no 

 longer of uniform colouring, all have the rmnicis form of high 

 (if not actually humped) 5th and 12th segments — head black, 

 some are coloured as in previous skin, i.e., the tubercles all 

 black, and with a bright gamboge area in the pale segments 

 between the trapezoidals. Some are inclined to lose this 

 colouring, but none are absolutely black. In others the yellow 

 tends to form a continuous band through segments 8 and g. 

 In these more highly coloured larvse the trapezoidal tubercles 

 are orange instead of black ; in some even in the 5th segment. 

 The most striking have very little yellow on the skin, but have 



