ORDER I 



RHYNCHOCEPHALIA 



149 



Naosaurus, Cope (Fig. 239). DifFers from the last in that the neural 

 spines bear transverse processes. Per- 

 mian ; Texas and Bohemia. 



Embolophorus^ Theropleura, Archaeo- 

 bolus, Lysorophus, Cope. Permian : 

 Texas. Stereorachis, Gaudry ; Calli- 

 brachion, Boule and Glengeaud. Per- 

 mian ; Autun, France. Known by im- 

 perfect remains apparently allied to 

 Dimetrodon. 



Sub-Order 3. 

 RHYNCHOCEPHALIA VERA. 



Abdominal rihs reduced tothreerelatively 

 large longitudinal series ; pubis and ischium 

 well ossified ; fifth metatarsal very mucli 

 shortened, and somewhat expanded. Mar- 

 ginal teefh in one or more uniform series. 



Fio. 243, 



Hy%)ero(hqmlon gordoni, Huxley. Upper Trias ; 



Elgin, Öcotland. A, Snperior aspect of skull, i/a- 

 li, Palate. C, Mandibular Symphysis from below. 



a, Orbit; md, Mandibular fork ; mx, Maxilla ; n, 

 Nasal ; pl, Palatine ; /imr, Preniaxilla ; s, Supia- 

 teniporal vacuity ; s', Lateral temporal vacuity), 

 (after Huxley). 



Fig. 239. 



Naosaurus daviger, Cope. Permian ; Texas. 

 Dorsal \'ertebrae, anterior and lateral aspects, I/4 

 (after Cope). 



Family 1. Rhynchosauridae. 



Skidl Short and broad, wiih a beak-like 

 ostrum formed by the downwardly curved, 

 slender, toothless premaxillae. Mamiibles 

 with a Single, and maxillae and palatines 

 with several longitudinal series of depressed 

 conical teeth. External nares conflueni. 

 Trias. 



Hyperodapedon, Huxley (Fig. 240). Body stout, upwards of 2 m. long. 



