Hemichordata was earlier considered as a sub-phylum under phylum Chordata. But now it is placed as a separate phylum under non-chordata. Hemichordata have a rudimentary structure in the collar region called stomochord, a structure similar to notochord.
This phylum consists of a small group of worm-like marine animals with organ-system level of organisation. They are bilaterally symmetrical, triploblastic and coelomate animals. The body is cylindrical and is composed of an anterior proboscis, a collar and a long trunk. Circulatory system is of open type. Respiration takes place through gills. Excretory organ is proboscis gland. Sexes are separate. Fertilisation is external. Development is indirect.
![Examples of Phylum Hemichordata Examples of Phylum Hemichordata](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiEKY2Vc6I8IJaEFcTdGM-cHDrqZf0ZelTZVrBVfzxNoCT3KdOlwnKq9Eh9vnCxwR_hLMpgaC6I5LwspwEas_b4QFUB6kcaokjEgKtHBZ741h1DkbgTNVN2cYfHn69RdySUDlBjHwCdwu8Yix5wntAz0K2HjwrWJvJpG8_LheeVG-EHr02fedg2KOr3/w640-h360/balanoglossus.png)
Examples of Phylum Hemichordata : Balanoglossus and Saccoglossus