Figure 4 in Revision of the smiling worms, genera Prosadenoporus Bürger, 1890 and Pantinonemertes Moore and Gibson, 1981 and description of a new species Prosadenoporus floridensis sp. nov. (Prosorhochmidae; Hoplonemertea; Nemertea) from Florida and Belize

Figure 4. Histological sections of Prosadenoporus floridensis sp. nov. Transverse sections through (A) the proboscis insertion, and (B) anterior proboscis showing proboscis nerves (arrowheads); (C) transverse section through the proboscis showing inner circular muscles; (D–E) transverse sections through the cephalic blood vessels, demonstrating ''valves'' and ''pouches'' (arrowheads); (F) transverse section through the vascular plug (arrowhead); (G) transverse section through the lateral nerve cord showing nerve cord muscles (arrowhead); (H) transverse section through the midgut region of a mature female showing large oocytes in the ovary; (I) longitudinal (sagittal) section through the frontal organ (arrowhead) and precerebral region (anterior to the left); (J–L) a series of transverse sections through the anterior (J), middle (K) and posterior (L) portions of the frontal organ showing lateral acidophilic regions (arrowheads). Notes: bgl, basophilic cephalic glands; cg, cerebral ganglia; cm, circular muscles; fo, frontal organ; icm, inner circular musculature; int, intestine; lm, longitudinal musculature; lnc, lateral nerve cord; lum, blood vessel lumen; oct, oocytes; pb, proboscis; pep, proboscis epithelium; rhc, rhynchocoel; rhd, rhynchodeum. Scales: (D–F), 25 mm; (A, B, C, G and J–L), 50 mm; (H–I), 200 mm.