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Psyche 
[September-December 
large, single prey were wrapped only after a lengthy period, i hr or 
more, had elapsed. It appears that the absence of vigorous movements 
by the prey is a necessary part of the stimulus situation for the onset 
of wrapping. 
Post-immobilization wrapping in other wandering spiders. — Our 
two species of Lycosa performed post-immobilization wrapping, 
whereas Schizocosa crassipes did not. We modified our original 
speculation that this behavior might be characteristic of the Lycosidae 
to the notion that it might be at least genus-specific. Even this is 
no longer tenable, in light of our preliminary observations on other 
species as well as data obtained by R. J. McKay (personal commu- 
nication). We now regard post-immobilization prey-wrapping as a 
behavioral adaptation that may be included in the repertoire of 
various unrelated wandering spiders that have specialized for spend- 
ing part or most of their time some distance above the ground on 
vegetation. 
Post-immobilization wrapping occurs after the prey has stopped 
struggling, occupies a relatively brief amount of time during the 
lengthy feeding process, and is used for prey only when the total 
volume exceeds some threshold value. These are the probable rea- 
sons why this behavior has not yet been reported in many species in 
which it is likely to occur. Authors specifically studying feeding 
behavior have seen post-immobilization wrapping in two other fam- 
ilies of wandering spiders — ctenids (Melchers, 1961, 1963) and 
theraphosids (Eberhard, 1967), although neither of these authors 
determined the function. 
A personal communication from E.-A. Seyfarth, that wrapping 
occurred in Cupiennius salei , called our attention to the work of 
Melchers (1961, 1963) on this ctenid species. (Comparison with our 
species was facilitated by our being able to view Melchers’ (1961) 
film of this behavior.) Post-immobilization wrapping by C. salei is 
very similar to what occurs in our Lycosa spp. as to the sequence of 
events and movements, stimuli releasing the behavior, etc. However, 
two differences are obvious : ( 1 ) C. salei waits for prey on a vertical 
surface. If it tumbles to the ground during prey capture, it carries 
the prey back up to an elevated point on the vertical surface — the 
glass wall of the terrarium in Melchers’ study. Individuals of our 
species never did the latter, but readily stayed on the ground to feed 
if the capture ended there. (2) The density and breadth of the 
swathing bands are much greater in C. salei than in our Lycosa spp. 
Points 1 and 2 are probably interrelated and suggest that this ctenid 
