The Collaborative International Dictionary
Scolithus
Scolithus \Scol"i*thus\ (? or ?), n. [NL., fr. Gr. skw`lhx a worm + li`qos a stone.] (Paleon.) A tubular structure found in Potsdam sandstone, and believed to be the fossil burrow of a marine worm.
Wiktionary
scolithus
n. (context paleontology English) A tubular structure found in Potsdam sandstone, believed to be the fossil burrow of a marine worm.