164 REPORT — 1859. 



member of the present order, which seems to have been the forerunner of 

 the next. 



Order VIII. Dinosauria*. 



Cervical and anterior dorsal vertebrae with par- and di-apophyses, arti- 

 culating with bifurcate ribs : dorsal vertebrae with a neural platform : sacral 

 vertebrae from four to six in number. The articular ends of the free vertebrae 

 are more or less flat ; but in the cervical become convex in front and concave 

 behind, in some species. The limbs are ambulatory, strong, long and un- 

 guiculate. The femur has a third trochanter in some. The species of this 

 order were of large bulk, and were eminently adapted for terrestrial life : 

 some, e.g., Jguanodon and probably Hylaosaurus, were more or less vegetable 

 feeders ; others, e.g., Megahsaurus, were carnivorous. The Dinosaurs ranged, 

 in time, from the lias (Scelidosaurus, Ow., from Charmouth) to the Upper 

 Greensand (Iguanodon). The Megahsaurus occurs in the lower oolite to 

 the Wealden inclusive. The latter formation is that in which the Dinosauria 

 appear to have flourished in greatest numbers and of largest dimensions. 



Order IX. Crocodilia. 

 Teeth in a single row, implanted in distinct sockets, external nostril single, 

 and terminal or subterminal. Anterior trunk-vertebrae with par- and di- 

 apophyses, and bifurcate ribs ; sacral vertebrae two, each supporting its own 

 neural arch. Skin protected by bony, usually pitted, plates. 



Suborder Ampliicodia \. 

 Crocodiles closely resembling in general form the long- and slender-jawed 

 kind of the Ganges, called Gavial, existed from the time of the deposition of 

 the lower lias. Their teeth were similarly long, slender, and sharp, adapted 

 for the prehension of fishes, and their skeleton was modified for more effi- 

 cient progress in water, by both the terminal vertebral surfaces being slightly 

 concave, by the hind limbs being relatively larger and stronger, and by the 

 orbits forming no prominent obstruction to progress through water. From 

 the nature of the deposits containing the remains of the so-modified Croco- 

 diles, they were marine. The fossil Crocodile from the Whitby Lias, de- 

 scribed and figured in the 'Philosophical Transactions,' 1758, p. 688, is 

 the type of these amphiccelian species. They have been grouped under the 

 following generic heads: — Teleosaurus, Mystriosaurus, Mac rospondy lies, 

 Massospondylus, Pelagosaurus, JEolodon, Suchosaurus, Goniopholis, Pozci- 

 lopleuron, Stagonolepis, &c. Species of the above genera range from the lias 

 to the chalk inclusive. 



Suborder Opisthoccelia \. 



.The small group of Crocodilia, so called, is an artificial one, based upon 

 more or less of the anterior trunk-vertebrae being united by ball-and-socket 

 joints, but having the ball in front, instead of, as in modern Crocodiles, be- 

 hind. Cuvier first pointed out this peculiarity § in a crocodilian from the Ox- 

 fordian beds at Honfleur and the Kimmeridgian at Havre. The Reporter has 

 described similar opisthoccelian vertebrae from the Great Oolite at Chipping 

 Norton, from the Upper Lias of Whitby, and, of much larger size, from 

 the Wealden formations of Sussex and the Isle of Wight. These specimens 

 probably belonged, as suggested by him in 184-1 and 1S42||, to the fore part 



* deivos, terrible ; aavpos, lizard. 



t «j»<?i, both ; ko'i\os, hollow : the vertebrae being hollowed at both ends. 



X o7ri<T0e, behind ; koZAos, hollow : vertebras concave behind, convex in front. 



§ Annales du Museum, torn. xii. p. 83. pi. xxi. 



|| " Report on British Fossil Reptiles," Trans. British Association for 1841, p. 96. 



