Figure 20. Sanjuannemertes aeilloaesi, new genus and species, holotype. (a) Transverse sections between 12 and 97 from anterior end of body, showing posterior portion of right dorsal ganglion, dorsal and lateral blood vessel; (b) cephalic furrow united from dorsal and ventral transverse grooves; (c) short canal of cephalic groove above the dermis; (d) posterior ocelli on cerebral sensory organ; (e) ocelli in the right side of the head and frontal glands; (f) cerebral sensory organ in the right side of the head; (g) cerebral sensory organ in the left side of the head and brain lobes; (h) posterior end of cerebral organ canal widened in its outer portion. Scale 100 mm (a–h). Abbreviations: ad, anterior cephalic groove formed by dorsal and ventral grooves united at mid-lateral portion of head; ao, anterior ocellus; br, brain; cb, cephalic blood vessel; cn, cerebral organ canal; cp, canal of cephalic groove in epidermis; cr, circular muscle layer of rhynchodeum; cv, cephalic nerves; cw, cerebral organ canal widened outward; dg, dorsal ganglion; dr, dermis; dv, dorsal blood vessel; eo, eosinophilic glandular mass; fg, frontal glands; gc, ganglionic mass; lv, lateral blood vessel; ne, nephridia; pn, proboscis nerve; po, posterior ocellus; ps, proboscis sheath; rc, rhynchocoel; rd, rhynchodeum; sa, sensory canal of cerebral sensory organ; st, stomach; vg, ventral ganglion; wa, wall of sensory canal of cerebral sensory organ.