u 



VBETEBRATA. 



Palxocetits from the Upper Greensand of Ely, Eng. "With these ex- 

 ceptions, the Order (according to our present knowledge) is confined to 

 the Tertiary and Recent Periods. The most numerous fossil relics 

 (teeth and ear-bones) have been found in the Red Crag, but evidently 

 washed out of Eocene strata. In the Miocene Period, the Dugongs and 

 Manatees were abundant and more widely distributed than now. Their 

 fossil bones have the solid structure of those of living herbivorous 

 mutilates. 



No. 175. Halitherium Schinzi. 



Skull, Femur, and Tooth. Tins herbivor- 

 ous animal, related to the Dugong, lived by the 

 sea-shore and the mouths of rivers. Remains 

 have been found in every deposit above the Cal- 

 caire Grossier (Middle Eocene). These specimens 

 were discovered in the Miocene at Flonheim, 

 Rhine Valley. Size, 8x8. Price, $5.00. 



Zeuglodon cetoides, Owen. 



Two Teeth. 



No. 176. 



This carnivorous whale 

 typified a distinct family intermediate between 

 Cetacea proper and Sirenia. Its teeth were 

 first described by Scilla in 1747 ; in 1836 by 

 Harlan under the names of Basilosaurus and 

 Squalodon ; and in 1839 by Owen, who first 

 determined the mammalian and cetacean na- 

 ture of the animal. When full grown, it was 

 probably seventy feet in length. The skull is 

 long and narrow ; the nostril single and look- 

 ing upward. The jaws are armed with teeth 

 of two kinds, set wide apart : the anterior have 

 subcompressed, conical, slightly recurved, 

 sharp, pointed crowns, and are implanted by a 

 ; single root ; the posterior are larger with more 



ftllllfll'l i compressed and longitudinally extended crowns 



conical, but with a more obtuse point, and with 

 both front and hind borders strongly notched 



\or serrated. The crown is contracted from side 

 ^1 I llll^'l '* ■Mlllllf to side in the middle of its base, so as to give 



its transverse section an hour-glass form. The 

 generic name refers to this structure. The 

 root of the posterior teeth has two fangs. The 

 mode of succession conforms to the general 

 mammalian type more than any existing carnivorous Cetacean ; i. e.^the decid- 



