Saccoglossus

Saccoglossus     is a genus of acorn worm (Class Enteropneusta). It is the largest genus in this class, with 18 species.

This genus is characterized especially by the concentric rings of muscle fibers in the proboscis. Many Saccoglossus can be found in coastal mud and sand habitat, often near bays. They dig tubes in the substrate, ejecting conical piles of castings in a spiral fashion.

Acorn worms of this genus are known for the production and accumulation of various halogenated phenols and pyrroles.

Species
Species include:
 * Saccoglossus apatensis Thomas, 1956
 * Saccoglossus aulakoeis Thomas, 1968
 * Saccoglossus bromophenolosus King, Giray and Kornfield, 1994
 * Saccoglossus horsti Brambell and Goodhart, 1941
 * Saccoglossus hwangtauensis Si & Kwang-Chung, 1935
 * Saccoglossus inhacensis van der Horst, 1934
 * Saccoglossus kowalevskii (Agassiz, 1873)
 * Saccoglossus madrasensis Rao, 1957
 * Saccoglossus mereschkowskii (Wagner, 1885)
 * Saccoglossus otagoensis (Benham, 1899)
 * Saccoglossus palmeri Cameron, et al., 2010
 * Saccoglossus porochordus Cameron, et al., 2010
 * Saccoglossus pusillus (Ritter, 1902)
 * Saccoglossus rhabdorhynchus Cameron, et al., 2010
 * Saccoglossus ruber Tattersall, 1905
 * Saccoglossus shumaginensis Cameron, et al., 2010
 * Saccoglossus sonorensis Cameron, et al., 2010
 * Saccoglossus sulcatus (Spengel, 1893)