Phylum key (cont.)Key to the Worms
Segmented - The body appears to be segmented (Fig. 1 & 2). They can either be cylindrical or flat. The insect family Diptera, which is not a segmented worm, may key out in this group, because it can have no legs and appears to have a wormlike body (Fig. 3 & 4). A head region can usually be detected on a Diptera larva (Fig. 3 & 4). Also look for a paired mandible.
NonSegmented - The body does not have any segmentation on it (Fig. 5-7). They can either be flat (Fig. 5) or cylindrical (Fig. 7) in shape. The anterior portion of the flatworms looks like a head, because of eye spots (Fig. 5).