THE SUBCLASS PARAPSIDA 



273 



Family Mosasauridae. Teeth conical, 

 pointed. 



Upper Cretaceous. Mosasaurus Conybeare, 

 Clidastes Cope, Platecarpus Cope, ?Sironectes 

 Cope, Macrosaurus Owen, Brachysaurus Willis- 

 ton, Baptosaurus Marsh, North America. Plio- 

 platecarpus Dollo, PrognatJwsauriis Dollo, Haino- 

 saurus Dollo, Mosasaurus Conybeare, Europe 

 (England, France, Belgium, Russia). Taniwha- 

 saurus Hector, New Zealand. 



Family Globidentidae. Teeth spheroidal, 

 rugose. Imperfectly known. 



Upper Cretaceous. Globidens, Gilmore, Europe 

 and North America. 



Tribe Amphisbaenia 



Worm-like or snake-like, burrowing lizards, 

 reaching a length of about one and one-half feet, 

 either legless or with short tetradactyl front limbs 

 immediately back of the skull. Body with 

 numerous rings and without scales, the tail very 

 short and blunt. Eyes minute. No postorbital or 

 temporal arch, the quadrates fixed by the ptery- 

 goids; squamosals and tabulars indistinguishable; 

 no postorbitals, lacrimals, or jugals; the nasals 

 large. No parietal foramen. Brain-case in front 

 partly enclosed by plates from frontals. Palate 

 without openings back of the nares. Stapes short 

 and stout. Vertebrae procoelous. 



A curious group of burrowing Uzards, moving 

 by vertical rather than lateral undulations. The 

 soUd skull with the palate firmly fixed, the im- 

 movable quadrates, and entire absence of arches, 

 together with the vestigial or absent limbs, are 

 characters almost as far removed from the typical 

 lacertiHan structure as are those of the snakes, 



