A REVISION OF THE PISAURIDAE OF THE UNITED STATES NY 
the summer and well into September. Farther south, mature males 
may be found in April. Low-growing vines and weeds at the edge 
of hillside woods offer favorable nursery sites for the early matur- 
ing individuals, especially where a southern exposure receives full 
benefit of the sun. Later in the season they are more widely scat- 
tered and are likely to be found on the bushes and low shrubs. 
In the construction of the nursery web and disposition of the 
egg sac, Pisaurina mira differs widely from those species 
of Dolomedes whose habits have been observed. In the latter, 
the female carries the egg sac until the young are ready to emerge, 
then attaches it to a convenient support and spins the nursery web 
around it. With Pisaurina mira, the nursery is usually 
constructed before the eggs are laid. A plant having a three-lobed 
leaf is often selected for the retreat, and there seems to be a de- 
cided preference for the poison ivy (Rhus). The middle leaflet, 
pulled down and fastened, serves as a roof; the two lateral leaf- 
lets, as the side walls (pl. 10, fig. 1), and a silken platform spun 
across the opening beneath, as the floor (pl. 10, fig. 2). Hanging 
back downwards from the lines that hold the leaves in position, 
the spider clutches her sac of eggs with her chelicera and embraces 
it with the third legs. The first and second pairs partially encircle 
the sac but the claws are caught in the supporting strands of the 
nursery and serve with the fourth pair, to support the burden. 
Threads from the spinnerets complete the attachment behind and 
serve in emergency as the only connection. The egg sac, the size 
of a cherry pit and snowy white when first made, is enlarged con- 
siderably by the hatching and growth of the young and acquires a 
dingy hue. 
Just before the eggs hatch, the sac is suspended in the retreat 
and the young, doubtless aided by the mother, escape through an 
opening in the bottom. To provide room—for the young moult once 
within the egg sac, soon after leaving it and again in about ten 
days—the silken floor of the chamber is pushed aside and new 
lines added which cover the outside and entangle nearby leaves (pl. 
11). Females confined with their sacs proved their ability to con- 
struct dome-shaped retreats entirely of silk within which they re- 
mained until the young emerged. Another specimen provided with 
a paper leaf patterned after the poison ivy, drew the parts together 
in the conventional manner and hung with her sac for several days. 
In some cases several nurseries are constructed before one is found 
to meet the exact requirements and it is due to this habit that the 
female is sometimes found wandering about with her egg sac. 
