a subphylum or phylum of chordates that contains only the lancelets, a group of small invertebrate marine fishlike animals. There are 23 species in two genera - Branchiostoma (Amphioxus) and Epigonichthys. About 5-15 cm long, lancelets have gill slits and a notochord that persist into adulthood, the notochord extending the whole length of the body and providing the main skeletal support. The pharynx is modified for filter-feeding" (109)