FIGURE 3 in Three new species of Glossobalanus (Hemichordata: Enteropneusta: Ptychoderidae) from western North America

FIGURE 3. Light micrographs of transverse sections of Glossobalanus hartmanae. A, Proboscis with conspicuous circularmuscle layer, radial muscle bundles, heart-kidney complex and ventral septum. B, Proboscis peduncle showing the ventrolateral pouches of the stomochord and short skeletal keel. C, Collar showing a midventral vascular plexus. D, Dorsal nerve cord of collar with dorsal roots. E, Posterior collar showing canals. F, Anterior pharynx with plicate gill-bar epithelium. G, Intestinal region with lateral septum and median gonads. Abbreviations: a, atrium; bv, blood vessel; cc, collar canal; cg, ciliated groove; cl, collar lumen; cv, cardiac vesicle; ds, dorsal septum; ep, epidermis; g, glomerulus; gb, gill bar; gbe, gill-bar epithelia; gd, gonad; gp, gill pore; mg, median gonad; lg, lateral gonad, ls, lateral septum; nc, nerve cord; nr, nerve roots; pbd, peribuccal diverticula; pc, proboscis coelom; pcm, proboscis circular muscles; phd, perihaemal diverticula; pl, pharynx lumen; plm, proboscis longitudinal muscles; pr, parabranchial ridges; s, stomochord; sc, skeletal cornua; sk, skeletal keel; tlm, trunk longitudinal muscles; vp, vascular plexus. Scale bars: A, C, F, G = 500 μm; B = 200 μm; D, E = 250 μm