During feeding, a muscular, tubelike pharynx extends out from the mouth and sucks food into the animal. There are often 2 primitive eyespots on the top surface of the head they sometimes appear “cross-eyed.” The mouth is located about midway down the underside of the body this is the only opening to the digestive tract. ![]() Often there are 2 earlike flaps on either side of the head. Their simple nervous system is concentrated at the head end. ![]() Their bodies are bilaterally symmetrical: They have a left and right side, and what amounts to a back, a belly, and a head (that is, they are not radially symmetrical like starfish and sea anemones). In Missouri, most are tan, brown, black, or gray (but they can be brightly colored elsewhere, and species that live in caves usually look pink). ![]() There are many species, but all have some traits in common. Turbellarians, or planarians, have primitive body plans.
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