MAMMALIA. 69 



Tertiary limestone in Jamaica, which is exhibited in Pier- Pier-case 

 case 29 (30). It is peculiar in possessing a complete set of 29 ( 30 )- 

 teeth, incisors and canines as well as premolars and molars. 

 Fragments of jaws, possibly of another species of the same 

 genus, occur in the Upper Eocene of Northern Italy. 



Pig. 65. — Skeleton of Halitherium schinzi, from the Oligocene of Hesse- 

 Darmstadt ; one twenty-fifth nat. size. (Case V.) 



The oldest known Sirenians are Eotherium and Eosiren 

 from the Middle Eocene of Egypt. Brain-casts, a plaster 

 cast of a skull, and other remains are exhibited in Pier-case 

 29 (30). 



Skeletons and stuffed specimens of the living manatees 

 and dugongs are placed in Case V and Pier-case 29 (30) for 

 comparison with the fossils. See " Guide to the Galleries 

 of Mammals," p. 84. 



Oeder VIII.— CETACEA. 



The fossil remains of whales, porpoises, and dolphins are Gallery of 

 placed with the living members of the Order in the Gallery z ^f^Dep't 

 of Cetacea (Department of Zoology). They are all very 

 fragmentary. 



The typical modern Balsenidse do not occur below the 

 Pliocene, where they are represented chiefly by ear-bones 

 (tympanies), of which a good series from the Bed Crag of 

 Suffolk is exhibited (Fig. 66). Small whalebone whales, 

 however, existed so long ago as the Oligocene period both in 

 Europe and North America, although there are no remains in 

 the collection. 



Teeth and bones of the toothed whales are more fre- 

 quently met with among fossils. All the kinds which still 

 live seem to have been in existence before the close of the 

 Pliocene period. Even the strange compact snouts of the 

 beaked whales, such as Mesoplodon, are common fossils in 

 the Pliocene Crag of England and Belgium, and a good 

 collection is mounted for exhibition. Some of the earlier 



