Multiple choice Which of the following characters are present in class Crustacea? Cephalothorax, gills and appendages Head, thorax, gills and appendages Cephalothorax, book gills and appendages Head and thorax, book gills and appendages - Reveal answer Fill a bubble to check yourself A Correct answer Explanation Crustaceans have a hard exoskeleton made of calcium. Thorax portion has two pairs of antennae, and three pairs of mouthparts. A pair of green glands excrete wastes near the base of antennae. The abdominal segments have swimmerets (swimming legs).