ORDER III 



ICHTHYOSAURIA 



165 



Sheppey and Bracklesham, England, and Cuise la Mothe France, are ascribed 

 to marine Pytlionidae which may have attained a length of 6 m. A vicarious 

 genus, Titanophis, occurs in the Eocene of New Jersey, and several genera 

 (Helagris, Cope ; Boavus, Litliophis, and Limnophis, Marsh) have been described 

 from the Eocene of Wyoming and New Mexico. Among the Upper Eocene 

 (or Oligocene) forms of France, Switzerland, and England may be mentioned 

 Palaeopylhon (Fig. 261) and Scyfalophis, Rochebrune, and Pcderyx, Owen. 



Palaeopython cadurcensis, Filhol sp. Phosphorite of Qiiercy, France. ^, Anterior. iJ, Lateral. C. Inferior. 

 D, Posterior aspect of vertebra, i/j. (c, Centrum ; d, Transverse process with costal tubercle ; sp, Neural spine ; 

 ^, Zyapophysis ; sa, Zygantrum ; zsp, Zygosphene.) 



One of the best preserved _ Miocene serpents is Heteropython euboeicus, 

 Eoemer, from Kumi, on the island of Euboea. Representatives of the 

 Cohibridae (JElapMs, Aldr. ; Coluber, Linn.), and Eryddae (Scaphophis, Roch.) 

 have been described from the freshwater Miocene of Oeningen, Steinheim, 

 Giinzburg, Haeder, Weisenau, Ulm, Sansan, Touraine, and other localities, as 

 well as from the lignites of Rott, near Bonn. A number of Eryddae and 

 Crotalidae are also known from the Miocene of Colorado and Oregon. All 

 known Pleistocene remains are identifiable with existing genera. 



Order 3. ICHTHYOSAURIA. {Ichthyopterygia}) 



Primitive marine reptiles with fish-like body, long head and tail, and no distinct neck. 

 Investing bones of temporal region contracting into a single broad arcade ; quadrate 

 fixed. Rostrum long and tapering ; orbits Ictrge, laterally placed, with sclerotic ring. 

 External nares separate, slightly in advance of orbits. Parietal foramen and supra- 

 temporal vacuities large. Teeth acutely conical, inserted in a continuous groove on 

 the maxillae and elongated premaxillae and mandibles, but sometimes wanting. Vomer 

 edentulous. Vertebrae numerous, very short, deeply amphicoelous. Bibs long, 

 abdominal ribs present, but sternum absent. Pectoral arch consisting of coracoids, 

 scapulae, clavicles, and a T-shaped inter clavicle. Limbs short, paddle-shaped, 

 sometimes with more than five rows of phalanges, and a layer of cartilage around 

 the carpals, tarsals, and phalanges. No dermal armour. 



^ Baur, G., On the morphology and origin of the Ichthyopterygia (Amer. Nat. voL XXI. p. 837), 

 1887 ; also Bericht, 20th Versamnilung Oberrhein. geol. Vereins (1887), p. 20 ; and Auat. Anz. 

 vol. X. (1894), p. 456. — Cope, E. I)., On the cranium of Ichthyopterygia (Proc. Amer. Assoc. Adv. 

 Sci. vol. XIX. p. 197), 1870. — Fraas, £., Die Ichthyosanrier der siiddeutschen Trias mid Jura 

 Ablagerungen. Tiibingen, 1891. — Die Haiitbedeckuug von Ichthyosaurus (Wiirtt Jahresh. p. 493), 

 1894. — Hawkins, T., Memoirs of Ichthyosauri and Plesiosauri. London, 1834. — Marsh, 0. C, On 

 Baptanodon, etc. (Amer. Joum. Sci. [3], vol. XVII. p. 86), 1879 ; also ibid. vol. XIX. (1880), p. 491 ; 

 and vol. L. (189.5), p. 405. — Merriam, J. C, Triassic Ichthyopterygia (Bull. Californ. Univ. vol. III. 

 p. 63;i, 1902. — Owen, R., Monograph of the fossil Reptilia of the Liassic Formations, Part III. 

 (Palaeontogr. Soc. ), 1881. — Monograph of the fossil Eeptilia of the Cretaceous Formations 

 (ibid.), 1851. — Seeley, H. G., On Ophthalmosaurus, etc. (Qnar. Journ. Geol. Soc. vol. XXX. p. 

 696), 1874.— On the skull of an Ichthyosaurus [ibid. vol. XXXVI. p. 635), 1880.— TAeorfor;'. C, 

 Beschreibung des kolossalen Ichthyosaurus trigonodon 7,u Banz. Munich, 1854. 



