VERTEBEATA 



105 



minute rudiments ; anterior limbs oar-like. 

 (MuHlata.) 



Elbow joint inflexible ; carpals discoid, 

 and, with the phalanges, separated 

 by cartilage ; lower jaw without as- 

 cending ramus ; 



Elbow joint flexible ; carpals and pha- 

 langes with close articulations ; 

 mandible with ascending ramus ; 



(2) Cetacea. 



(3) Sirenia. 



AA. Posterior limbs present; ungual phalanges 

 compressed and curved on one or all the 

 feet.* ( Unguiculata.) 



j3, Carpal and tarsal bones generally in linear 

 series. 



Y, Teeth without enamel ; no incisors. 



Limbs ambulatory ; hemispheres small ; (4) Edentata. 



yy, Teeth with enamel ; incisors present. 



No postglenoid process; mandibular con- 

 dyle not transverse; mastication 

 proal ; limbs not volant ; hemis- 

 pheres small ; 



Anterior limbs volant; hemispheres small; 



A postglenoid process ; mandibular con- 

 dyle transverse ; mastication orthal ; 

 scaphoid and lunar bones not coal- 

 esced ;t hemispheres small, smooth ; 



A postglenoid process; limbs not volant, 

 with a scapholunar bone ; mastica- 

 tion orthal; hemispheres larger, 

 convoluted; (8) Garnivord. 



(5) Glires. 

 (6) Chiroptera. 



(7) Bunotheria. 



