FIGURE 2 in Three new species of Glossobalanus (Hemichordata: Enteropneusta: Ptychoderidae) from western North America

FIGURE 2. Light micrographs of transverse sections of Glossobalanus williami. A, Proboscis with radial muscle bundles, heart-kidney complex, and ventral septum. B, Proboscis heart-kidney complex with a distinct lumen and poorly developed glomerulus. C, Proboscis peduncle showing the proboscis canal and obtuse skeletal keel. D, Anterior collar showing only a dorsal septum. E, Mid collar with parabuccal diverticula and lateral skeletal cornua. F, Posterior collar showing canals to the first pair of gill atria. G, Pharynx with conspicuous gill slits. H, Pharynx showing only primary gonads. Abbreviations: cc, collar canal; cl, collar lumen; cv, cardiac vesicle; dep; dorsal epidermal pocket; ds, dorsal septum; ep, epidermis g, glomerulus; gb, gill bar; go, gonad; gp, gill pore; nc, nerve cord; nfl, nerve-fiber layer; pbd, peribuccal diverticula; pc, proboscis coelom; pcm, proboscis circular muscles; pcp, proboscis canal (and pore) of the peduncle; phd, perihaemal diverticula; pl, pharynx lumen; plm, proboscis longitudinal muscles; pn, anterior neuropore; pr, parabranchial ridges; s, stomochord; sb, skeletal body; sc, skeletal cornua; sk, skeletal keel; tc, trunck coelom; tlm, trunk longitudinal muscles; vs, ventral septum. Scale bars: A, E, F = 500 μm; B, C = 100 μm; D, G, H = 250 μm.