Fam. 7. Worm-Thricozoa, Moles.
Claws, sharp incisors or rodent teeth, with lateral incisors or false molars; live exclusively under the earth, and cast up the mould.
Fam. 8. Crustaceous Thricozoa, Shrews.
Paws, rodent teeth, with small lateral incisors and canine teeth. Many burrow passages without throwing up the soil.
Fam. 9. Ptilotal Thricozoa, Bats.
Alary membrane between the feet and anterior digits; pointed canine and incisor teeth.
Order 4. Sarco-Thricozoa—Ungulata.
3570. Body large and heavy; teeth stunted, molars uniform, tolerably obtuse; feet fin-or hoof-like; mostly udders, rarely mammæ.
Fam. 10. Ichthyoid Thricozoa, Whales.
Skin naked; no hind feet; two horizontal caudal fins; toes of the anterior feet surrounded by a common skin; no auditory conchs; posteriorly two udders. All live in the sea.