The wafer trapdoor spiders (superfamily Cyrtauchenioidea, family Cyrtaucheniidae) are a widespread family of spiders that lack the thorn-like spines on tarsi and metatarsi I and II (the two outermost leg segments) found in true trapdoor spiders (Ctenizidae).
. . . . . . . . . . . . . . vs . . . . . . . . . . vs . . . . . . . . . . . . . . . vs MECICOBOTHRIIDAE
Mecicobothriidae is of the few mygalomorphae families in CA which possess a longitudinal thoracic groove ( http://scabies.myfreeforum.org/about1015.html )