THE GENUS ACRONYCTA AND ITS ALLIES. 
75 
trapezoidals being very long, those on ii very short, on 5-10 
nearly twice the diameter of the larva in length, the others 
longer ; the posterior trapezoidal hairs on 12 have the appear- 
ance of belonging to the anterior trapezoidal set, being equally 
long and merging with them. 
In the 2nd skin the larva is blacker, hairs longer, tubercles 
so large on 2nd, 5th, and especially on 12th, as to look like 
humps, the dorsal hairs are black, the lateral white ; the dorsal 
band is pale lemon yellow (almost white) visible only on the 
pale segments, till the larva is well grown, when this area on the 
dark segments is paler than the rest of the segment, and there 
is then on 6 and 7 a trace of a vertical white mark in front and 
behind the spiracular tubercles. The post-spiracular tubercle 
is still of good size, the area below it is paler, and the effect of 
the longitudinal form of the sub-spiracular tubercle is to show 
a paler line above the darker tubercles, the tubercles (anterior 
trapezoidal) of 5 already approach one another. Those of 12 
are large, but the area between them is but slightly paler than 
the rest of the larva, 13 is pale rufous, slightly paler than 12, but 
there is no white cross on 12, no white diamonds between 
trapezoidals, no rich colour of 13, and the hump on 5 is not so 
distinct as in tridens. 
In the 3rd skin it has the psi appearance of the full-grown 
larva, the yellow dorsal band is continuous on 3-4,6-11, and on 
13, but the yellow is of a brownish tint on 8 and g ; the anterior 
trapezoidals on these segments are now very small. There is 
now a distinct hump on 5th segment, but still recognisable as 
consisting of anterior trapezoidals ; most of the tubercles 
carry 5-8 hairs, those of dark segments rather the longest and 
generally black. The sides are rufo-fuscous, marbled with 
yellowish fuscous, with black tubercles and two pale vertical 
lines in front and behind the spiracular tubercles. The sub- 
spiracular tubercles of ii and 12 are yellow, others black. 
In the 4th and following skins it gradually assumes the well- 
known appearance of the full-grown larva. 
Its habits of pupating seem to be identical with those of 
tridens already noticed. The pupa (PL III., figs, i, \b) is 
not to be distinguished with certainty from that of tridens. 
Psi usually has four spines on each side forming the ventral 
portion of the anal armature, whilst tridens usually has but 
three, but just as tridens has not unfrequently four, so psi has 
at times only three. Tridens is also usually smaller and more 
delicate and transparent in appearance, and I cannot with cer- 
