Figure 6

Schematic dorsal view of the central nervous system of H. psammobionta . Anterior side is up. Abbreviations: 1, double root of rhinophoral nerve; 2, buccal commissure with median nerve; 3, presumed headshield nerve with parallel nerve leading into double optic connectives; 4, cerebropedal connective with parallel static nerve and anterior pedal nerve at its base; 5, visceral loop with branch forming presumed pleuropedal connective; 6, static nerve running parallel to cerebropedal connective; bg, buccal ganglia; bn, buccal nerve; cpg, cerebropleural ganglion; ey, eye; hn, headshield nerve; lag, (lateral) accessory ganglia of headhield nerve; ln, labiotentacular nerve; lnag, accessory ganglia of labiotentacular nerve (more anterior); lpag, left parietal ganglion; opg, optic ganglion; opgn, nerves of optic ganglion; pcm, pedal commissure; pg, pedal ganglion; pnd, dorsal pedal nerve; rhn, rhinophoral nerve; rnag, accessory ganglia of rhinophoral nerve (more posterior); rpag, right parietal ganglion; sc, statocyst; subg, subintestinal ganglion; supg, supraintestinal ganglion; vg, visceral ganglion; vn, visceral nerve(s); vl, ‘visceral loop’.