Solitary Ascidian or Tunicate (Class Ascidiacea)
Their name comes from the Greek 'askidion' which means 'leather
wine bag'. Hence their other name 'tunicate' from the leathery
'tunic' of their outer skin. Essentially, they are a hollow sack
made of tough leathery tissue, with two openings. The creature
creates a current through these openings, passing water through an
internal filter which traps minute edible titbits.
