564 MANUAL OF ZOOLOGY. 



so that they must have been unable to roll themselves up. It 

 is rare at the present day to meet with any Armadillo over 

 two or three feet in length ; but the length of the Glyptodon 

 clavipes, from the tip of the snout to the end of the tail, was 

 more than nine feet. 



Fig. 217. Glyptodon clavipes. Pleistocene deposits of South America. 



All these gigantic South American Edentates occur in Post- 

 tertiary deposits. Older, however, than any of these is the 

 Macrotherium. This is a gigantic Edentate, intermediate in 

 some respects between the Pangolins and Orycteropus, and 

 found in certain lacustrine deposits of France, of Miocene age. 



Order IV. Sirenia. This order contains only the living 

 Manatees and Dugongs, and is of little geological importance. 

 The HaUtkcrium, however, of the Eocene, Miocene, and Plio- 

 cene Rocks is a large form, intermediate between the African 

 Manatee and the Dugong. 



Order V. Cetacea. The Cetacea, also, are of little geological 

 importance. Remains of Dolphins (Ziphius) and of Whales 

 (Balanodori) are found in Miocene deposits ; and numerous 

 ear-bones of Whales occur in the Red Crag of Suffolk (Plio- 

 cene). The most remarkable, however, of the extinct Cetacea 

 is the Zeuglodon of the American and Maltese Miocene de- 

 posits. This was an enormous toothed Whale, about seventy 

 feet in length ; but unlike any of existing Cetaceans, it had 

 the posterior teeth implanted by two distinct fangs or roots. 

 By Owen, Zeuglodon is regarded as the type of a distinct family, 

 intermediate between the Cetacea and the Sirenia. 



Order VI. Ungulata. The Hoofed Mammals are repre- 

 sented in past time by so many extinct forms that it will be 

 wholly impossible here to do more than merely allude to some 

 of the more important genera. 



The earliest-known Ungulates occur in the Eocene Rocks, 

 where the order is represented by very numerous and interest- 

 ing forms, the more important of which are Pliolophus, Palceo- 

 therium, and Anoplotherium. 



