FIGURE 4. A in Peanut worms of the phylum Sipuncula from the Nha Trang Bay (South China Sea) with a key to species

FIGURE 4. A. Antillesoma antillarum, lateral view, introvert everted. B–D. Apionsoma misakianum. B) lateral view, introvert everted; C) lateral view, introvert retracted; D) hook. E–F. A. trichocephalus. E) head (white arrowhead - rudimental tentacle on dorsal arc.); F) hook. Scale bars: A–B, 5 mm; C, 2 mm; D, 20 µm; E, 100 µm; F, 20 µm.