Phylum Nemertea (Ribbon Worms)

Approximate Number of Species: 900

Largest: Lineus longissimus reaches a length of 9.8 feet (3 meters)

Smallest: Species of the genus Carcinomertes reaches lengths of only 0.08 inches (2 mm)

References:

Brusca RC & Brusca GJ (2003) Invertebrates (Sinauer Associates, Inc., Publishers, Sunderland, MA) 2nd Ed.

Gibson R (1982) British Nemerteans (The Linnaean Society of London, Cambridge University Press, Cambridge).