Cheselden describes the preliminary illustrations in his Chapter VIII "Comparative sceletons, etc.", and his descriptions are quoted here. The illustrations comprise three introductory plates, four plates each (frontispiece, headpiece, initial letter, and tailpiece) to the Address to the Reader, Introduction, and eight Chapters, and a final plate. All the animals are shown as skeletons. Numbers have been allotted for convenience of reference, though not used bij Cheselden; the initial letters are grouped together at nos. 35-44.