258 PETRIFACTIONS AND THEIR TEACHINGS. CHAP. III. 



In 1841, the elaborate and critical examination of all the 

 saurian vertebrae from the Wealden, collected by myself and 

 others, in the able " Reports on the British Fossil Reptiles," 

 established some important diagnostic characters by which 

 the isolated parts of the spinal column of several genera of 

 reptiles, whose remains are found promiscuously imbedded in 

 those deposits, might be identified. But the determination of 

 the cervical, anterior dorsal, lumbar, and terminal caudal of 

 the Iguanodon is not, even now, satisfactorily accomplished ; 

 for although, in my earlier attempts to interpret the dissevered 

 parts of the skeletons which were from time to time exhumed, 

 certain large vertebrae of dissimilar forms were vaguely assigned 

 to the Iguanodon, rather from their collocation with un- 

 doubted bones of that reptile, and the absence of remains of 

 the extremities of other genera to which they could have be- 

 longed, than from their anatomical characters, many of these 

 bones have since been referred to distinct genera, upon grounds 

 scarcely more valid. 1 



Among the vertebrae I have obtained of late years, are 

 cervicals, anterior dorsals, and posterior caudals, which so 

 closely approximate in their essential characters to the known 

 vertebrae of other parts of the spinal column of the Iguano- 

 don, as to render it highly probable that they belong to that 

 animal ; and although, in the absence of connected portions 

 of the different regions of the spine, absolute certainty cannot 

 be obtained, the typical affinity of the bones in question ap- 

 pears to support this view of the subject, rather than that which 

 assigns them to distinct genera, of which no other less ques- 

 tionable vestiges have been discovered in the same deposits. 2 



1 See " Reports on British Fossil Reptiles," vol. for 1841, pp. 8894. 



2 In a work like the present, I can only state the general result of a 

 careful examination of all the specimens to which Dr. Melville and 

 myself could obtain access ; and I would refer to my " Memoir on the 

 Osteology of the Iguanodon and Hylseosaurus in " Philos. Trans, for 

 1849," p. 271, for figures and details. I may add that, during the 

 last year my private collection has been enriched by upwards of thirty 

 vertebrae, among which are larger and more perfect dorsals of the Igua- 

 nodon than any previously discovered ; others are cervicals, dorsals, and 

 caudals, of allied genera. Should Providence grant me life and health 

 to continue these investigations, I hope to obtain some highly important 

 results, and advance our knowledge of the structure and economy of the 

 stupendous saurians of the Wealden, whose osteology is still but very 

 imperfectly worked out. 



