Mammalia in the 10th edition of Systema Naturae
The Mammalia in the 10th edition of "Systema Naturae" forms one of six classes of animals in Carl Linnaeus's tenth reformed edition written in Latin. The following explanations are based on William Turton's translations who rearranged and corrected earlier editions published by Johann Friedrich Gmelin, Johan Christian Fabricius and Carl Ludwig Willdenow: Animals that suckle their young by means of lactiferous teats. In external and internal structure they resemble man: most of them are quadrupeds; and with man, their natural enemy, inhabit the surface of the Earth. The largest, though  fewest in number, inhabit the ocean." Linnaeus divided the mammals based upon the number, situation, and structure of their teeth; mammals have the following characteristics: Oldfield Thomas scrutinized Linnaeus's chapter on mammals in 1911 and attempted to find missing type species and type localities. Primates. Primates have four cutting upper parallel fore-teeth, except in some bat species which have two or none; solitary tusks in each jaw, one on each side; two pectoral teats; two feet and hands; flattened, oval nails; and they eat fruits. Bruta. Bruta do not have fore-teeth, but tusks, feet with strong hoof -like nails; move slowly and eat mostly masticated vegetables. Ferae. Ferae usually have six conic fore-teeth in each jaw, longer tusks, grinders with conic projections, feet with subulate claws, and feed on carcasses and prey on other animals. Bestiae. Bestiae have indefinite numbers of fore-teeth on the sides, always one extra canine, an elongate nose used to dig out juicy roots and vermin. Glires. Glires have two cutting fore-teeth in each jaw, but no tusks, feet with claws formed for running and bounding, and eat bark, roots, and vegetables, which they gnaw. Pecora. Pecora do not have  upper, not many lower cutting fore-teeth, hoofed, cloven feet, and feed on herbs which they pluck, chewing the cud; four stomachs, a paunch for macerating and ruminating food, a bonnet for reticulating and receiving it, an omasus or maniplies of numerous folds for digesting it, and an abomasus or caille, fasciate, for giving it acescency and preventing putrefaction. Bellua. Bellua have obtuse fore-teeth, hoofed feet, move heavily, and feed on vegetables. Cete. Cete have some cartilaginous, some bony teeth, no nostrils but a fistulous opening in the anterior and upper part of the head, pectoral fins instead of  feet, horizontal, flattened tails, no claws, live in the ocean, and feed on mollusca and fish.