Balanoglossus in Mashail Island described it as a worm-like holothurian. The discovery of gill-slits in this animal by Kowalewsky (1865) led to creation of a special class Enteropneusta by Gegenbaur (1870). Bateson (1885) included them in Phylum Chordata. Hyman (1959), however, placed them near Echinodermata and gave Hemichordata a status of an independent phylum. This simple organism shows affinities with several diverse groups. Balanoglossus is a tuberculos or burrowing and exclusively marine animal. It is found in shallow waters between tide marks along the coast of warm and temperate oceans. Balanoglossus clavigerus is a U-shaped excavated in a sandy bottom Nemertines
Nerve net of the divergence with Cnidaria and Ctenophora or they lost the function of the gene encoding Nav channels. As a result, Porifera contain Cav channels which allows for intercellular signaling, but they lack Nav channels which provide for the conductance of action potentials in nerve nets. Nerve nets are found in species in the phyla Cnidaria (e.g. scyphozoa, box jellyfish, and sea anemones), Ctenophora, and Echinodermata. Cnidaria and Ctenophora both exhibit radial symmetry and are collectively known as coelenterates. Coelenterates diverged 570 million years ago, prior to the Cambrian explosion, and they are the first two phyla to possess nervous