 Organ complexity as seen in "Pseudunela cornuta" (regarding excretory and reproductive features, at least) represents innovations that evolved in small, mesopsammic marine acochlidians.The central nervous system of "Pseudunela cornuta" is euthyneurous and composed of the paired cerebral, rhinophoral, optic, pedal, pleural, buccal and gastro-oesophageal ganglia as well as three distinct ganglia on the visceral nerve cord, plus a presumed osphradial ganglion.All ganglia excluding the buccal and gastro-oesophageal ganglia are situated pre-pharyngeally.