2 54 THE HISTORY OF CREATION. 



Mammals, are most closely allied to Hoofed animals, and 

 more especially agree with tliem in the absence of the 

 decidua and in the tufted placenta. Even at the present day 

 the river-horse (Hippopotamus) constitutes a kind of transi- 

 tion form to the Sea Cows (Sirenia), and from this it seems 

 most probable that the extinct primary forms of the Cetacea 

 are most closely allied to the Sea Cows of the present day, 

 and that they developed out of Pair-hoofed animals, which 

 were related to the hippopotamus. Out of the order of 

 Herbivorous whales (Phycoceta) — to which the sea cows be- 

 long, and which accordingly, very probably, contain the 

 primaiy forms of the legion — the other order of Carnivorous 

 whales (Sarcoceta) appears to have developed at a later 

 period. But Huxley thinks that these latter were of quite a 

 different origin, and that they arose out of the Carnaria 

 through the Seals. Among the Sarcoceta, the extinct gigantic 

 Zeuglodonta (Zeugloceta) — whose fossil skeletons some time 

 ago excited great interest, it being thought that they were 

 " sea serpents" — are pi'obably only a peculiarly developed 

 lateral branch of genuine whales (Autoceta), which com- 

 prise, besides the colossal whalebone whales, the cachalot or 

 spermaceti whales, dolphins, narwhals, porpoises, etc. 



The third legion of the Indeciduata, or Sparsi-placentalia, 

 comprises the strange group of the animals poor in teeth 

 (Edentata) ; it is composed of the two orders of burrowers 

 and sloths. The order of Burrowers (Effodientia) consists 

 of the two sub-orders of ant eaters (Vermilinguia), to 

 which the scaled animals also belong, and the girdle 

 animals (Cingulata), which were formerly represented by 

 the gigantic Glyptodons. The order of SlotJis (Tardigrada) 

 consists of the two sub-orders of the small, still living 



