572 CHORDATA 



evidence would seem to point to tlic ungulates, creodonts, or carnivores. The 

 toothed and whalebone whales may ha\e had different ancestries, their resem- 

 blances being the result of convergence. 



Sub Order I. ZEUGLODONTA. Extinct (eocene) forms with hcterodont 

 dentition, the posterior teeth two-rooted. Sub Order II. DENTICET,E, 

 toothed whales, carnivorous, some having but two teeth. Dclphinus* dolphins; 

 Clohiocephalns* black fish; Monodon, narwal, male with a long maxillary tusk. 

 Physcter macroccphahis, sperm whale, pursued for the spermaceti, an oily mass 

 situated in the 'chair' between the cranium and the snout, as well as for amber- 

 gris, formed in the intestines. Sub Order III. ]\IYST.^CP>TI, whalebone 

 whales, with baleen. Balcrnoptcra* rorquals and fin backs. B. sihbaldi* the 

 largest whale, eighty-live feet long. Bahcna, right whale. 



Order XI. Prosimiae (Lemuroida). 



Linne united with the true apes a small group of animals known as lemurs, 

 because of similarity in body form and climbing habits, liecause they had 

 grasping hands and feet (opposable thumb and great toe), and frequently nails 

 on some of the toes. To-day many set them aside as a separate order on account 

 of their lower organization. They have a less-developed cerebrum, uterus 

 bicornis, and a diffuse olacenta. Further peculiarities are the peculiar and 



Fig. 62o.^Stenops gracilis, slender loris (from Brehm). 



variable dentition (Chiromys MH, Lemur l\l^. Nocturnal habits have re- 

 sulted in large eyes, which give these animals a most striking appearance. A 

 distinction from the primates is the connexion of orbital and" temporal ca\ ities 

 beneath the os.seous postorbital ring. Usually there are a pair of pectoral 

 mamma!;, to which are added in many species a pair in the abdominal or inguinal 

 region, the latter alone occurring in Cliiromys. All come from the Indian and 

 Malagassy regions. 



Chiromyid,*:, digits long, all except the great toe with claws; Chiromvs, 

 aye-aye_. T.^RSriD.'E, second and third hind toes clawed. Tarsiiis, East Indies, 

 differs in closed orbits and discoidal placenta. Lemurid.e, second hind toe 



