Fig. 13

Thaliaceans. a A chain of mature blastozooids of an unidentified salp species. Image by Ed Bierman (https://www.flickr.com/photos/edbierman/5005294079). b A young pyrosome colony (species unknown). Image by Nick Hobgood (https://commons.wikimedia.org/wiki/File:Combjelly.jpg). c Left: illustration of tailed, free-swimming larva (oozoid) of Doliolum denticulatum, showing larval tail and 9 body wall muscle bands. Adapted from Godeaux [114]. Right: illustration of an individual of the sexual generation (gonozooid) of Doliolum denticulatum. Anterior to the left. m1–m8, muscle bands 1 through 8; at, atrial aperture; at l, atrial aperture lobes; br, branchial (oral) aperture; br l, branchial aperture lobes; br s, branchial sac; dt, dorsal tubercule; end, endostyle; h, heart; i, intestine; n, nerves; ng, nerve ganglion; ov, ovary; pp, peripharyngeal band; p br, peribranchial atrium; sg, stigmata (gill slits), s gl, subneural gland, so, sense organs; st, stomach, tes, testes. Adapted from: Tunicata. In: A Guide to the Shell and Starfish Galleries (Mollusca, Polyzoa, Brachiopoda, Tunicata, Echinoderma, and Worms). London: Department of Zoology, British Museum (Natural History), 1901. Larva and gonozooid not drawn on same scale