14 AURIVILLIUS, A NEW GENUS OF HARPACTICIDA. 
the same branch af the second pair of feet in the preceding 
stage. Fourth pair of feet (P1. IV. Fig. 12) consisting of two one- 
jointed branches and very similar to the second and third pairs of 
feet, when first coming forth. Fifth pair of feet wanting. 
In the fourth stage of development, the young has eight- 
jointed body and five pairs of feet. Anterior antenne 
eight-jointed and like those of the female; posterior having 
received one spine more on the outer margin and being 
tbus quite similar to those of the full-grown animal. The 
branches of the first pair of feet remaining two-jointed. First 
joint of this as well as that of all the other pairs of feet separated 
from the two others that constitute the terminal joint. The 
outer branch. of the second pair of feet, (PI: IVI Eistl3j 
has received one seta more at the inner margin of the outer 
joimt, but is two-jointed and still destitute of one spine at 
the outer margin; its inner branch is one-jointed and has 
received two sete more at the apex, but the outmost of 
these is almost invisible and curved like a small eclaw. It 
therefore constitutes, as it were, a medium between the forms 
of the male and female. The outer branch of the third pair 
of feet (P1. IV. Fig. 14.) is two-jointed, has received one 
spine more on the outer margin and another seta on the 
inner, so that it now completely resembles the outer branch 
of the second pair of feet in the preceding stage of develop- 
ment; inner branch one-jointed, with two sete at the apex. 
The outer branch of the fourth pair of feet two-jointed, the 
inner one-jointed, with two sete at the apex. The basal 
joint of the outer branch bearing a spine on the external margin, 
and the terminal joint having three spines on the outer mar- 
gin, two set&e at the apex and a similar one on the inner mar- 
gin. It differs thus from the third pair of feet in this stage 
by having one seta less on the inner margin, and from the 
same pair of feet in the preceding stage by having one spine 
more at the outer margin. Fifth pair of feet consisting of 
two laminar branches, separated by a low furrow, destitute 
of joints and placed on the same basal part. Outer lamina 
bearing four small setxe, but the inner only one at the 
rounded margin. 
In the fifth stage, the young almost completely resem- 
bles the female, but may be distinguished by its size as 
well as by the fact that the inner branch of the first 
