Phylum Hemichordata has been recently given the status of separate phylum because it lacks a true notochord. It was previously considered as subphylum under the Phylum Chordata. All are marine with bilaterally symmetrical, organ system level of organization, triploblastic, and eucoelomate. The body is made up of anterior proboscis, collar, and a long trunk. Respiration by gills, the circulatory system is of open type. Excretion is by proboscis gland, dioecious and fertilization is external, development is indirect.
Examples : Balanoglossus (Tongueworm), Saccoglosssus.