THE DICYNODONTIA- 





Fig. T8. — ^Tlie pelvis and hind-limb of, A., DromcBUS ; B., an omithoscelid reptile, such as 

 Iguanodon, or Hypsilophodon ; and C, a Crocodile. The bird's limb is in its natural 

 position, as is that of the Omithoscelid, though the metatarsus of the latter may not, in 

 nature, have been so much raised. The Crocodile's limb is purposely represented in an 

 unnatural position. In nature, the femur would be turned out nearly at right angles to 

 the middle vertical plane of the body, and the metatarsus would be horizontal. The letters 

 are the same throughout. 7Z, ilium ; Zs, ischium ; Pb, pubis ; a, anterior process, &, 

 posterior process, of the ihum ; T)\ inner trochanter of the femm- ; T, tibia ; F, fibula ; 

 As^ astragalus ; Ca, calcaneum. /., //., ///., IV.., the digits. 



VIII. The Ornithosceltda. — The very remarkable extinct 

 reptiles which constitute this group, present a large series of 

 modifications intermediate in structure between existing Hep- 

 tilia and Aves. 



