1010.] 



The Quadrate-incus Theory applied to the Cynodontia. 



137 



practieallij as a single fulcrum for the lower jaw (of Fig. 7, B), especially if 

 there was a light movement between the angularc and the dentary; and 



; 



2 



Fig. 6. Morphology of the mandibular condyle, coronoid and angle in Mesozoic Therapslds 

 and Mammals. Scale various. 



D., dentary. 



p. ang., processus angularis. 



sin. corono-condylar sinus. 



con. condyle. 



cor. coronoid. 



No. 3. Lower jaw of a Triassic Cynodont reptile, Diademodon mastaciis, after Broom. In- 

 cipient condyle and corono-condylar sinus, angular process well developed. 



No. 2. Lower jaw of a Triassic Cynodont, Tribolodon freresi, aiter Seeley . Large coronoid 

 with sloping anterior border. 



No. 4. Lower jaw of a Triassic Promammal (?) Dromatherium sylvcstre, after Osborn. 

 Condyle prominent, coronoid very broad and sloping anteriorly, corono-condylar sinus {sin.) 

 incipient. 



No. 5. Lower jaw of a Triassic Promammal (?) Microconodon temiirostris, after Osborn. 

 Angular process incipient. 



No. 1. Lower jaw of a Triassic Promannnal (?) Karoomys hrowni, after Broom. Angle 

 and condyle well developed. 



No. 7. Lower jaw of a Middle Jurassic mammal Phascolotherium bucklandi, after Osborn. 

 Angle inflected, condyle sessile, corono-condylar sinus well marked; coronoid very broad, 

 sloping anteriorly. 



No. 6. Lower jaw of an Upper Jurassic mammal Docodon striatus, after Marsh. Condyle 

 pedunculate but not raised very much above the level of the teeth, angle well developed, coronoid 

 verj' broad and sloping anteriorly. 



