Cephalon (noggin): typically with well-defined border, glabella tapering forward, preglabellar field present, opisthoparian sutures, natant hypostome, and genal spines; but exceptions include eyeless forms (Conocoryphidae), proparian forms (Norwoodiidae), rounded genal angles and gonatoparian sutures (Menomoniidae).
Thorax(upper body): typically 12-17 segments. (double to triple 6 pack. Impressive)
Pygidium (Lower body, aka the fun and gross parts): typically micropygous, transverse, pleural field nearly flat, with distinct pleural grooves; but exceptionally isopygous
15mm rare trilobite on 50mm slab