Page:Popular Science Monthly Volume 33.djvu/824

804 silky matter. The doors are cut in a conical shape, to fit the flare of the cylinder, and will not yield under pressure from without. The exterior of the door is uneven and rough, like the ground round it, whereby the attention of enemies is diverted. Inside it is tapestried like the nest itself. The hinge, made of a compact silk, possesses great resisting power, and such elasticity that the trap infallibly falls back as soon as it ceases to be held up. The place of a lock or bolt is taken by a series of little holes, like needle-pricks, arranged in a circle around the side of the door opposite the hinge. When the trap is down, the closing is so exact that the most delicate instrument can not be introduced into the interstice without danger of injury. If one tries to raise the trap, the spider, clinging to the walls of the pit, and inserting its claws into the holes of the cover, will make the most desperate efforts to keep it shut. In the evening, the spider comes out stealthily from its retreat, and goes to hunt its game in the fields. Having finished its meal, it returns to its home, lifts the trap-door with its claws, and disappears from view in an instant.

 (Moggridge). D, the door which closes naturally by its own elasticity and weight; m, marks of the spider's claws when she has held it down from inside.

A much larger and finer species of cteniza than the one just