The chordates (Chordata, from the Greek ??????? khordota 'with rope') are a phylum of the animal kingdom that have a dorsal cord, called notocorda or notocordium, of turgid cells, ? Hollow neural tube in dorsal position, gill slits and tail, at least at some stage of the embryonic stateCephalochordates (Cephalochordata from the Greek ?????? kephalé, "head" and ????? khordé, "rope"), acranials or amphioxus, also called leptocardia (class Leptocardii), are a subphyle of chordates. They live half-buried in the coastal sandy bottoms where they swim freely.