CHORD ATA — VERTEBRATA — AIAMMALS 399 



These are probably descended from the unguiculates. They 

 include : — 



(i) Zeuglodontia, — primitive Eocene whales with certain 

 characters which are transitional to primitive Carnivora. The 

 typical genus Zeuglodon has been found in the Upper Eocene 

 of North America, Europe, North Africa and in probably equiv- 

 alent strata of New Zealand. 



(2) Odontoceti, — toothed whales, including (a) squalodonts, 

 confined to the Middle Tertiary ; (b) dolphins, porpoises, 

 etc., not known in the fossil state ; (r) narwhals, not known 

 in the fossil state ; (d) sperm and beaked whales, — Upper 

 Eocene to the present. 



(3) Mystacoceti — whale-bone whales, including the gray, 

 fin, hump-backed and right whales and the rorquals — are 

 known from the Miocene to the present. 



Order 11, Primates 



Arboreal, or bipedal walking mammals, with thumb and often 

 great toe opposable to the other digits. Digits usually five 

 and provided with flat nails, very rarely with claws. Eye 

 surrounded by a complete bony ring. 



The primitive forms of the Primates are related to the Insec- 

 tivora of the unguiculate section of mammals. Sub-order 

 (i) Lemuroidea (Lower Eocene to present) includes the extinct 

 families Notharctidai and Anaptomorphidae, both Lower to 

 Upper Eocene of North America and Europe. The surviving 

 family of Lemuridae, the lemurs, has been found in the fossil 

 state only since the beginning of the Pleistocene. 



Sub-order (2) Anthropoidea (Lower Miocene to the present) 

 includes {a) the " broad nostril " or New World monkeys of 

 South America to Mexico ; examples of these are the marmosets, 

 not known in the fossil state, the capuchins, the howlers, spider 

 and squirrel monkeys, some of which are known as fossils from 

 the Pleistocene; {b) the "narrow nostril" or Old World 



