298 



PALEONTOLOGY. 



apply to the productions of human art, if we can view such 

 examples of mechanical contrivance, united with so much 

 economy of expenditure, and with such anticipated adapta- 

 tions to varying conditions in their application, without feel- 

 ing a profound conviction that all this adjustment has resulted 

 from design and high intelligence." 



Besides the various localities of the Wealden strata in 

 England and Germany, remains of the Iguanodon have been 

 found in the Upper Greensand near Cambridge and near 

 Maidstone. 



All trace of dinosaurian reptiles disappears in the cre- 

 taceous series. 



Order IX. — Ckocodilia. 



Char. — Teeth in a single row, implanted in distinct sockets ; 

 external nostril single and terminal or sub-terminal. 

 Anterior trunk vertebrae with par- and di-apophyses, 

 and bifurcate ribs ; sacral vertebrae two, each supporting 

 its own neural arch : this arch usually articulated by 

 suture. Skin protected by bony, usually pitted, plates. 



The extinct reptiles of this order have given evidence of 

 its nature and extent, of which the few surviving forms 

 afforded no suspicion. No less than three well-marked modi- 

 fications of the vertebral joints of the back-bone have been 

 recognized in the great series of Crocodilian reptiles, now 

 embraced in a view which goes back to the beginning of the 

 mezozoic period. 



In one family both articular surfaces, a and b, of the cen- 

 trum or vertebral body are concave, as indicated by the dotted 

 lines in fig. 103, i ; and the term ' amphiccelia,' meaning 

 cupped at both ends* expresses this character. In a second 

 family the front surface (ib. z, a) is convex, the hind one, b, 

 concave : this modification is expressed by the term i opistho- 



* AmpJii, both ; hollos, hollow ; the vertebra being hollowed at both ends. 



