In the development of vertebrate animals, Pharyngeal or<unk> es form on the endodermal side between the branchial arches, and pharyngeal grooves (or clefts) form from the lateral ectodermal surface of the neck region to separate the arches. The<unk> es line up with the clefts, and these thin segments become gills in fish.
Branchial pouch
Branchial arch
Pharyngeal pouch 
First pharyngeal arch
Thyroglossal duct
Aortic arches
Notochord
Rathke's pouch