From what we know of the vertebral column of _Thalattosaurus_ it appears that the animal had a relatively short neck and a long dorsal region, the proportions being nearly those in the vertebral column of some mosasaurs. Only the anterior portion of the caudal region is known. The slender, rounded neural spines with well-developed articulating processes seen here are not such as commonly appear in forms with a highly specialized sculling tail, and it is hardly probable that a caudal fin of large size was developed. The anterior limbs evidently formed paddles of moderate size. The posterior pair may have been larger, in compensation for lack of a strong sculling tail. It is, however, possible, that as in _Geosaurus_ (of the thalattosuchian crocodiles) the hind limbs were not typically natatory, and the distal end of the tail was vertically expanded. No specimens have yet been found which are well enough preserved to show any remains of the stomach contents, and we have no definite evidence concerning the food of the thalattosaurs, more than is furnished by the general structure of the animal. The character of the paddles, the form of the skull, and the presence of slender prehensile teeth in the terminal portions of the jaws would indicate that they fed in part upon some swiftly moving prey which was caught by a quick snap of the jaws, deglutition being assisted by the curved teeth of the pterygoids. The heavy vomerine and posterior mandibular teeth may have been used for crushing the light shells of ammonites, which existed in vast numbers in the same seas. CHAPTER XIII RHYNCHOCEPHALIA In some of the small islands near the northeast coast of New Zealand certain small and peculiar, lizard-like reptiles, known as tuateras, have long been known. For many years they were supposed, even by scientific men, to be real lizards, so much do they resemble in external appearances and in habits the lizards of other parts of the earth. It was early observed, however, that they presented certain remarkable internal differences from the real lizards or Lacertilia, though it was not till about twenty-five years ago that the importance of these differences was recognized by the late Professor Cope, who separated them into a distinct order quite co-ordinate with the lizards, crocodiles, and turtles. These little reptiles, seldom reaching a length of two feet, have now become so scarce that the New Zealand government protects them by law from unnecessary destruction; nevertheless it will probably be only a short time before they become extinct, the end of a long genealogical line. No other living reptiles have retained more of the old-fashioned or primitive characters than this _Sphenodon_ or _Hatteria_, as the animal is called, and because of them it is of peculiar interest to zoölogists, and especially paleontologists.