ANNIVERSARY ADDRESS OF THE PRESIDENT. CI 



analogy with anything previously observed in reptiles. The charac- 

 ters of these osselets are quite in conformity with this descrip- 

 tion ; they are irregularly hexagonal, protuberant, and covered with 

 four concentric bands of smooth, rounded tubercles. As the diameter 



of these osselets is only about ^th of an inch, it is certainly a 

 very curious fact that the Placosaurus rugosus of Gervais, founded 

 upon the discovery in France of such minute osselets in direct con- 

 tact with the cranium, of which, combined together, they formed a 

 protecting plate or covering, should have been traced into Switzer- 

 land by means of the osselets alone, though in this case detached and 

 isolated. If this identification be well-founded, it is only natural to 

 expect that other vestiges of the Placosaurus may be hereafter dis- 

 covered ; and at all events such a fact is a striking illustration of the 

 wisdom of the caution which Sir C. Lyell has given us, not to assume 

 that certain animals have never lived because we have been unable to 

 find their fossilized remains. Palaeontology has done much to unravel 

 the ancient natural history of the world, but it has yet much more 

 to do. Of the other fossils described by M. Pictet, some were bones 

 of a head, found by MM. Gaudin and De la Harpe at Mauremont, 

 and which, though not without much difficulty, M. Pictet refers to 

 a lost type of Saurians, closely related to the Iguanas. The reason 

 of the difficulty in establishing this analogy is the striking resem- 

 blance of the inferior maxillary to that of an Ophidian ; but, as the 

 intermaxillary cannot be classed with Ophidian remains, the upper 

 and lower maxillary evidently belonged to the same species ; and as 

 all the bones were so closely associated together, the inference seems 

 well 'founded, that they belonged to a pleurodont iguana, of the 

 size of the living iguanas, characterized by a flattened muzzle shaped 

 like a horse-shoe, the nostrils being large and widely-separated; 

 by a series of small teeth on each pterygoid; by slender jaws 

 armed with conical detached teeth, of which the anterior were very 

 acute, thin, and slightly curved backwards. Having given these 

 details, M. Pictet exhibits a wise reserve by refraining from giving 

 a generic name to the animal until further discovery has provided 

 more complete data. Four vertebra?, obtained by Professor Morlot 

 in the breccia of Saint-Loup, are next noticed ; two are comparatively 

 large, and two smaller : the dimensions of the largest are, breadth, 

 1-02 in. ; height, 1*06 in. ; length, measured from one articulating 

 surface to the other, half an inch nearly — and these in the smaller 

 are similar in proportion, the height and breadth being nearly the 

 same, viz. '55 of an inch. M. Pictet states that the large ver- 

 tebrae, compared with those of Python molurus, appear to exhibit 

 an almost perfect identity, excepting that the vertebrae of the 

 living serpent are a little wider and shorter than those of the 

 fossil; the differences between the fossil and the vertebrae of a 

 Python figured by Professor Owen, are, however, greater. He 

 then points out the analogies of the fossil with the recent genus 

 Eryx and the fossil genus Palerycc, observing that he would have 

 classed the small vertebrae, if alone, with Paleryx rhombifer of 

 Owen, but that the larger vertebrae seem to have belonged to a more 



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