The question about the phylum arthropoda is incomplete, but it likely asks for the classes of arthropods and how their bodies are divided. Here are the major classes of the phylum Arthropoda and their typical body divisions: Insecta: Body divided into three main parts: head, thorax, and abdomen*. Arachnida: Body divided into two main parts: cephalothorax (fused head and thorax) and abdomen*. Crustacea: Body typically divided into two main parts: cephalothorax and abdomen*. Some have a distinct head, thorax, and abdomen. Myriapoda: Body divided into two main parts: head and a segmented trunk*. This class includes centipedes (Chilopoda) and millipedes (Diplopoda). 3 done, 2 left today. You're making progress.