tiitrodudion to Aiiiiiial JMorphotogy. 45 



Falkland seals, &c. In the North Atlantic, Gadidce and 

 Clupasidoe, Porpoises and Dolphins, Rorquals and Whales, 

 abound. In the ^lediterranean, Labroids and Dolphins, 

 Scomberoids, &c. In the North Pacific, Otaria, Enhydris, 

 and Cataphracta. In the middle Atlantic, Plcctognathi, 

 Manatus, Petrels, Pteropods, and Cephalopoda. In the 

 Indian Ocean, Buccinidae, Dugongs, Hydroids, Tubipora, 

 Rhinodon, Siluroids, Squamipinnes, Corals, and Echinoder- 

 mata. In the Middle Pacific, are Corals and Holothurians 

 in abundance. In the South Atlantic, the Proboscis Seal, 

 the Cape Whale, &c. In the South Pacific, Physeter and 

 Whales, also Polyzoa and Brachiopoda.* 



Distribution in time, or Historical Zoology, is an im- 

 portant branch of Zoolog}^, but one imperfectly known, 

 owing to the impossibility of the preservation of soft 

 parts in a fossil form. In the annexed table I have 

 endeavoured to represent the order in which the 

 various classes of the animal kingdom appear to have 

 been developed, and their proportional importance in 

 the life of each of the past periods of the world's 

 history as far as is yet known. The study of extinct 

 forms of life is called Palaeontology. 



* I am largely indebted to the works of Schmarda for this summaiy. 

 {Die Geographische Verbreitung der Thiere, Wien, 1853 ; and Zoologie, 

 1871, Bd. I, p. III.) 



