The Dysderidœ is a small family of spiders occupying in a certain respect an intermediate postion between the Tetrapneumones and the Dipneumones; the openings to the tracheæ are just behind the lung-slits, so that they may appear to have four lungs. The eyes are six in all of our forms. The mandibles are not small, in Dysdera quite large. The male palpi are quite simple in structure.