Diagram of a lancelet. The mouth is surrounded by a circle of tentacles; below the notochord is a row…
"Lateral view of Amphioxus. The notochord runs from tip to tip. t., Tentacular cirri; G., reproductive…
"Section of Ampioxus, fr, fin ray; ct, connective tissue; nc, notochord, ; snc, supraneural…
"Side view of Amphioxus: fs, fin supports; nc, notochord; ot, oral tentacles."—Finley,…