1 1 36 CLASS REPTILIA. 



correctly shown in the figure of the type skull. The single de- 

 scribed species indicates an animal about three feet in length. 

 This genus serves in some respects to connect Hyper odapedo7i with 

 Sphenodon. 



Family Sphenodontid^e. — The least specialised family of this 

 suborder is solely known by the existing New Zealand genus 

 Sphenodoii (Hatteria), of which the cranium is shown in fig. 1039. 

 According to Professor Huxley's definition, this genus is character- 

 ised by the divided nares ; the presence of a single tooth on either 



side of the premaxillary 

 beak, which was not 

 sheathed in horn ; by 

 the single row of pal- 

 atine teeth ; and the 

 amphiccelous vertebrae. 

 In the palate the ptery- 

 goids unite anteriorly 

 with the vomer to 

 exclude the palatines 



Fisr. io^Q. — Right lateral view of the cranium of Sphenodon r ,1 j • t« 



Punctata, of New Zealand. (After Giinther.) from the median line. 



Additional distinctive 

 features are found in the presence of intercentra between all the 

 vertebrae ; in the large size and the lateral position of the orbits ; 

 the well-developed parietal foramen ; and the large size of the supra- 

 and infratemporal fossae (fig. 1039). The humerus is remarkable 

 as having both an entepicondylar and an ectepicondylar foramen. 



The Tuataras, as these lizards are called by the Maories, are medium- 

 sized reptiles of extreme rarity, and with nocturnal habits. The alveolar 

 border of the dentary bone of the mandible is received in the groove 

 between the palatine and maxillary teeth, and in old individuals becomes 

 as hard and polished as the teeth themselves, of which it eventually dis- 

 charges the functions. 



Suborder 3. Hom^eosauria. — This group includes several 

 genera of Mesozoic Reptiles, in which the premaxillae did not, 

 apparently form a beak, and the ribs were devoid of uncinate 

 processes. The dentition is acrodont ; but the nature of the 

 palatal dentition is unknown. The vertebrae are amphiccelous, 

 and Dr Baur considers that intercentra were present. 



Family Hom^eosaurid^e. — The type family is definitely known 

 from the Kimeridgian Lithographic slates of the Continent, and is 

 characterised as follows. The body is shaped like that of ordinary 

 Lizards ; the skull is comparatively broad and short, with oval nares, 

 and a complete postorbital bar ; there are no tusk-like teeth in the 

 premaxillae or mandible ; and the pes is of normal structure. The 



