With regard to teeth , you have doubtless often observed those that distinguish the cubitus of the arm of most Lamellicorn beetles: these vary in number from one , as in Trox suberosus , to seven , as in Geotrupes autumnalis ; but the most universal number is three : in some species of Geotrupes , as G. stercorarius , &c., the third tooth from the apex, and those that follow it, may be called double .
— from An Introduction to Entomology: Vol. 3 or Elements of the Natural History of the Insects by William Kirby