Metabonellia

Metabonellia is a genus of marine spoon worms in the family Bonelliidae. It is a monotypic genus and Metabonellia haswelli is the only species. It is commonly known as the green spoon worm and is found in shallow waters around Australia.

==Description== The female worm has a sac-like trunk with a length of about and a width of . In front of the mouth is an extensible proboscis of about with a forked tip. The proboscis has a ciliated groove on the underside along which food particles are passed to the mouth. Behind the mouth, and close to the nephridium, which is raised on a protuberance, are two chetae (bristles), the bases of which are buried in the muscle. The body wall has transverse rows of papillae with flattened tops. The colour of the trunk is a dark, greyish-green, the proboscis is rather paler, and the edges of the forked tip are whitish. In life, the shape and dimensions of the worm are difficult to ascertain because it is constantly wriggling about. The ovarian tissue is situated alongside the ventral blood vessel and the nephridium consists of several interconnecting sacs.