Undine--a female water-spirit without a soul, with which she might be endowed only by marrying a mortal and bearing a child. (<Latin _unda_, wave.) Werwolf--a person who, according to mediæval superstition, became voluntarily or involuntarily a wolf and in that form practiced cannibalism. (<A. S. _wer_, man + _wulf_, wolf.) Wraith--a fantom of a living person, supposed to be ominous of that person's death. Lamia--a female demon or vampire that enticed youths and fed upon their flesh and blood. (Classical mythology.) Merrow--a mermaid. (Irish mythology.) Monaciello--the house-spirit of Naples. Nightmare--an evil spirit once supposed to oppress people during sleep. Called also Incubus. (<A. S. _niht_, night + _maere_, a nightmare.) Ogre--a demon or monster that was supposed to devour human beings. (<French _ogre_. The derivation is uncertain.) Ouphe--an elf or fairy. (<the Scandinavian. A variation of _oaf_ = elf.) Pigwidgeon--a very small fairy. Sprite--a spirit of the earth or air. Sylph--originally, a being, male or female, living in and on the air and intermediate between material and immaterial beings. (Used by Paracelsus. The word is undoubtedly of Greek origin.) =The Boggart= In the house of an honest farmer in Yorkshire, named George Gilbertson, a Boggart had taken up his abode. He here caused a good deal of annoyance, especially by tormenting the children in various ways. Sometimes their bread and butter would be snatched away, or their porringers of milk be capsized by an invisible hand; for the Boggart never let himself be seen; at other times the curtains of their beds would be shaken backwards and forwards, or a heavy weight would press on them and nearly suffocate them. The parents had often, on hearing their cries, to fly to their aid. There was a kind of closet, formed by a wooden partition on the kitchen stairs, and a large knot having been driven out of one of the deal boards of which it was made, there remained a hole. Into this one day the farmer's youngest boy stuck the shoe horn with which he was amusing himself, when immediately it was thrown out again, and hit the boy on the head. The agent was, of course, the Boggart, and it soon became the children's sport (called _laking with Boggart_) to put the shoe horn into the hole and have it shot back at them.