Presence of hepatic portal system is a character of chordates: S. No. Chordata Non -chordata 1. Post anal tail is usually present. Usually absent. 2. Notochord present at some stage or replaced by a back bone. Notochord or back bone absent 3. Pharyngeal gill slits present at some stage of life These are usually absent 4. Heart ventrally placed Dorsal, lateral, or absent 5. Closed blood vascular system Open, closed or absent 6. Hepatic portal system present Absent 7. Hemoglobin in RBCs Hemoglobin in plasma or absent 8. Hollow nervous system Solid nervous system 9. Single, dorsal nerve cord without ganglia Double, ventral nerve cord bearing ganglia.