It forms the tubes secreted by phoronids, who live in those tubes.  It makes up the setae, or bristles, protruding from annelids such as the clam worm and sandworm.  Taking its name from the Greek for "tunic," it is composed of acetylglucosamines linked in beta-1,4 manner.  
It forms the tubes secreted by phoronids, who live in those tubes.  It makes up the setae, or bristles, protruding from annelids such as the clam worm and sandworm.  Taking its name from the Greek for "tunic," it is composed of acetylglucosamines linked in beta-1,4 manner.  FTP, name this natural polymer that is found in the beak-like mouth of a squid, the cell walls of fungi, and the exoskeletons of insects and arthropods
It forms the tubes secreted by phoronids, who live in those tubes.  
chitin