Different types of nests of trap-door spiders. "a" is represented the nest of a French species of "Atypus", one of the Atypidae; this is included here merely for contrast; "b" represents the cork type of nest; Moggridge believed that in this type the tunnel is always simple, but Atkinson ('86) describes a branched nest with a door of the cork type. The following have the door of the wafer type as follows: "c", a single-door, un-branched wafer nest; "d", a single-door, branched wafer nest; "e", a double-door, unbranched wafer nest, and e1, the lower door of the same; "f, g," and "g1", three double-door, branched wafer nests, "f "and "g" differing in the form of the second door, shown at "f1", and "g2".