1972] 
Fergusson — Hypochilus thorelli 
193 
scrambled into the lampshade. The female positioned her legs so 
that they held her away from the substrate, with her abdomen in- 
clined away from, and her cephalothorax parallel to, the substrate 
(Figure 7). The male approached from the front and maneuvered 
between the substrate and the female’s cephalothorax, so that the 
dorsal side of his abdomen was in close proximity to the ventral side 
of her cephalothorax. The pair was turned in such a way that it 
was not possible to see the manner of insertion of the pedipalps. After 
3 minutes, the male disengaged, but remained in the web. Both re- 
mained in crouching positions inside the web until the end of the 
observation 2.5 hours later. I cannot definitely say whether or not 
sperm transfer took place, as the female died a week later without 
depositing eggs. 
Since the single observed case of mating took place with such ap- 
parent ease, it may be that the other cases observed involved females 
that had already mated and were not receptive. The female observed 
mating had been captured on 7 August and may not have had an 
opportunity to mate. 
Visual signals are not important in courtship behavior. Web vi- 
brations are the only obvious signals employed. Pheromones may 
possibly be released by receptive females upon receiving tactile sig- 
nals from the males. 
Courtship and mating patterns are those that are to be expected 
of a sedentary species with poor vision. Courtship is generalized, in- 
volving no elaborate displays on the part of the male, who alerts the 
female by simply pulling on the web. The mating position assumed 
is the “Dysdera embrace” common to web-building araneomorphs 
(Gertsch, 1949). 
Oviposition. Eggs are deposited several weeks after mating. (I 
found the first egg sac on 9 September.) The eggs are surrounded 
by a slightly flattened sac of tough, opaque silk about 6 to 8 mm by 
4 to 5 mm, with a continuous seam dividing it into two halves along 
the long axis. Covering the opaque silk is a layer of finely meshed silk, 
in which are embedded bits of wood, leaves, moss, small flakes of 
stone, and lichens so that the white sac itself is scarcely visible (Fig- 
ure 8). The entire sac is suspended at one end by one or two thick 
strands of silk and several fine strands so that it dangles from the rock 
surface, or it is held fairly securely to the rock surface by a number 
of strands attached at several different points. The covering of the sac 
usually matches the adjacent rock surface. At Dry Falls, I observed 
two sacs one foot apart. One of these was on a section of rock cov- 
ered with moss ; the sac was covered primarily with moss. The other 
