288 
Psyche 
[September 
it seems likely that at some seasons a greater proportion of mature 
spiders may be taken. Like other species of Trypargilum (see below), 
T. arizonense is not specific in its prey choice. Represented in our 
sample were at least 13 genera representing 6 families, and in one 
cell 7 species from 3 families were found. However, a decided 
preference was shown for vagabond or wandering spiders (especially 
Thomisidae), with only a few snare-building species taken. This 
suggests that T. arizonense hunts for spiders crawling on grass, 
flowers and foliage, also encountering there a certain number of 
snare-builders involved in activities away from the web. 
Table 2. The prey of T. arizonense : 212 spiders from 17 cells 
of 13 nests, Tucson, Arizona, July- August 1965. Determinations by 
Dr. H. W. Levi; specimens deposited in the Museum of Compara- 
tive Zoology, Harvard University. 
Salticidae (23) 
A gassa — 2 
Habronattus — 5 
Metaphidippus — 7 
Phidippus — 2 
Synemosyna — 1 
undet. juveniles — 6 
Thomisidae (177) 
Ebo — 1 
Misumenops — 97 (inch 61 juv.) 
Philodromus — 2 (juv.) 
undet. juveniles — 77 
Prey Preferences in the Genus Trypargilum. The marked and 
differing prey choices exhibited by members of this genus (see Krom- 
bein, 1967) and the reasonably adequate quantitative data on prey 
in past literature (records exist for 10 of the 12 Nearctic species 
and subspecies) make possible an attempt at consolidation of prey 
preference data in tabular form in hopes of revealing such trends 
as might occur in the genus. The results of this survey are presented 
in Table 3. The Trypargilum species are arranged in groups ac- 
cording to the classification of Richards (1934) and Sandhouse 
(1940), a system based on adult morphology. (It is worth noting 
that larval morphology, while incompletely known, appears to follow 
the same subdivisions (Evans, 1957, 1959).) For ease of comparison 
of prey records, the family level was chosen; identifications of lower 
spider taxa, especially in the older literature, are less reliable, and 
the taxonomy (and biology) of many genera remains unstudied. 
Oxyopidae (6) 
Oxyopes tridens Brady — 3 
Oxyopes sp. — 3 (juv.) 
Clubionidae (1) 
undet. juvenile — 1 
Dictynidae (1) 
Dictyna — 1 
Araneidae (4) 
undet. juveniles — 4 
