1969] 
Levi and Levi — Sicarius 
3 
in desert areas and from there a few species have invaded neighboring 
savannah land. The sparing use of silk (Fig. io) may also be an 
adaptation to the periodically sparse food supply and protein intake 
of desert inhabitants. 
Here two observations are reported. During the first the spider 
was left undisturbed ; during the second, to facilitate photography 
and observation, the spider’s work was interrupted. 
The spider under observation belongs to Sicarius sp. “no. I,” 
originating in Tucuman Province, Argentina. The female is the 
same individual reported on in the previous paper (Levi, 1968.) 
On 5 April 1968, at 8 a.m. a basal masonry disc was found on 
the paper lining of a vertical side of the plastic polystyrene container. 
One edge was 5 mm high, the opposite rim missing. From time to 
time the female scratched in the sand on the bottom of the container, 
throwing sand grains underneath her abdomen and sometimes rocking 
her abdomen from side to side. At 10 a.m. the spider was clinging 
to the upper rim of the disc tapping the lower rim with the tip of 
her abdomen, but it could not be seen whether spinnerets were in- 
volved or the anal tubercle. The mouth was definitely not used. 
At 8 p.m. (20 h) the disc was complete but the lower rim still lacking. 
On 6 April in the morning, no change was noticed; the spider had 
not worked during the night. On 7 April, in the morning, the upper 
wall was higher, about 1 mm high, and strongly concave. The lower 
rim was only slightly raised above the basal disc. The spider was 
buried. At 5 P.M. ( 17 h) the spider was seen clinging to the cup, not 
moving; at 8 p.m. (20 h) the female had moved slightly and a yel- 
lowish clump of eggs was seen inside the cup. The female now at- 
tached silk threads criss-cross over the top of the cup. She touched 
her spinnerets to the rim of the cup then drew a thread to the center 
and returned to the rim. Light seemed to disturb her and she stopped 
working. At 4:30 a.m. on 9 April, the lid was plastered over and 
the spider was slowly digging in the sand. At 7 A.M. the female was 
still digging, but in a different place; after digging a few strokes she 
stopped for a long time. At 8 130 a.m. the female was found buried, 
but not in the place where she had been digging. 
Although it could not be seen exactly how the sand was incorpo- 
rated into the wall of the cup, the mouthparts were not used. It is of 
interest that the eggcase was started on 5 April and finished on 9 
April, over a time span of four days, the female interrupting her work 
at intervals to return later. The construction of the eggsac of most 
spiders observed is started and completed within several hours. The 
