Ontogenetic changes in
cribellum spigot number and cribellar prey capture thread stickiness in the spider family Uloboridae.
Cribellum very wide, with narrow spinning fields (Fig.
Griswold (1990) addressed the higher level taxonomic question of the familial relationships of Phyxelidinae by emphasizing four character systems: the nature of the cribellum; the presence, form, number, and position of processes on the male palpal tibia; the pattern of tarsal and metatarsal trichobothria; and the form of the tracheal system.
9, 27, 29), rather than a cribellum found in "true amaurobiids," Tamgrinia, Arctobius, and some Macrobunus, or two patches of setae as in the subfamily Coelotinae, Ageleninae, and the family Cybaeidae.
It is only after reeling appears regularly in the repertoire of orbweavers (after the loss of the
cribellum among Araneoidea), that selective forces can help to mold this new tactic.
Spiracle just anterior to cribellum, about 0.4 3 as wide as cribellum plate (Fig.
18-23): cribellar plate bipartite, each field about a quarter as wide as long and separated by a narrow seam (about 0.1 x of a field length); seam and posterior plate margin sclerotized (in male, cribellum almost as wide as in female but with nonfunctional fields).
Opisthosoma 1.21 long, 0.54 wide, fine detail of anal tubercle, spinnerets and
cribellum not clear, situated ventrally, advanced from the posterior margin (Figs.