138 
Psyche 
[June 
viously. In such cases, courtship is likely to be very brief : the female 
will accept the male after 30-60 sec. of courtship. The initial phase 
of mating behavior, the courtship dance, can be observed with a wider 
variety of partners: females laden with eggs, females that have laid 
erggs, females of a different Phidippus species, females in glass vials, 
and even simple models of females such as hemispheres of modelling 
clay with a pair of wires as appendages (Drees, 1952). When a pre- 
viously mated female is used, courtship is not likely to last long and 
may end violently: the female will run away from the male or jump 
at him as she does at prey. Prolonged courtship can be seen with 
females confined in transparent vials, and with models of the female. 
A glass or plastic hemisphere 15-20 cm in diameter provides a 
suitably-sized observation chamber in which the spiders are always 
in full view. The chamber should have a rough textured floor as 
adult P. coccineus refuse to move or move unnaturally on a slippery 
surface. It is possible to use the spider’s preference for moving upward 
to introduce animals into the chamber with a minimum of disturbance: 
the spider climbs into a vial placed over it in the home jar, and 
climbs into the chamber when the open end of the vial is fitted into 
a hole in its floor. As the spider is likely to orient toward the observer 
when he is moving, it is advisable to shield writing movements and 
to observe from a constant position, with a light intensity differential 
to further obscure the observer. The Dazor Floating Magnifier unit, 
which combines a wide-angle lens and fluorescent light, is very suitable 
for this purpose. 
Results 
The courtship display of various Phidippus males ( apacheanus , 
clarus, coccineus , opifex) has a common basic pattern. The male 
begins his display by holding the carapace very high, shifting the 
abdomen to one side, and raising the first pair of legs. In this position, 
he moves before the female, stopping after each few steps. The male 
advances in a zig-zag pathway, shifting his abdomen to the other side 
at the end of each oblique approach. Throughout, the dancing male 
flicks his forelegs up and down, holding them wide apart at first and 
bringing them closer and closer together as he nears the female. 
Then, with forelegs held almost parallel before him, he touches the 
female cautiously once or twice. If the female remains still at this 
Explanation of Plate 8 
Figs. 11-12. Phidippus opifex (McCook), female, total length 14 mm. 
The female is tan, the male is black with light gray dorsum of carapace 
and abdomen. (The white rings in the eyes are reflections of the light used.) 
