Description of stone worm-pipe and works with him it is possible to look here
http://artnow.ru/ru/gallery/208/17888/picture/0/473260.html
http://artnow.ru/ru/gallery/208/17888/picture/3/442585.html
http://artnow.ru/ru/gallery/208/17888/picture/0/473260.html
http://artnow.ru/ru/gallery/208/17888/picture/3/442585.html