Teeth various: incisors and tusks often wanting in one or both jaws : grinders of one sort: toes large, covered with hoofs.

* No incisors in the upper jaw; eight in the lower: two middle toes separate: frontal bones furnished with horns: ruminate.

† Horns hollow', growing on a bony core; persistent.

21. Bos

Horns smooth; directed laterally at first, afterwards recurved: body thick and heavy: limbs strong: tail moderately long, terminated by a tuft of hair: four inguinal mammae.

22. Ovis

Horns rough and angular; directed backwards and laterally, more or less spirally twisted: chin without a beard: limbs rather slender: tail moderately short: two inguinal mammae.

23. Capra

Horns rough and angular; directed upwards and backwards: chin bearded: tail short: mammsB two.

†† Horns bony and solid: deciduous.

24. Cervus

Horns branched or palmated; while growing covered with a soft velvety skin: body and limbs slender : four inguinal mammae.

** Six incisors in each jaw: two middle toes soldered in one: no horns: do not ruminate.

25. Equus

*** Six incisors in each jaw; lower ones projecting forwards: four toes on each foot; two middle ones large and hoofed, lateral ones much smaller and not touching the ground.

26. Sus

Tusks exserted, inclining both upwards and to one side: snout elongated, and truncated at the extremity: body covered with stiff bristles.