FOSSIL REPTILES. 279 



are of moderate length, and nearly equal. In the land-tor- 

 toises they are nearly equal, and all remarkably short. But 

 in the sea- tortoises they are strongly elongated, and those of 

 the fore feet form a pointed fin, as they go on increasing from 

 the thumb to the medius, and then decreasing. This is exactly 

 to be observed in the tortoise of Glaris ; but it is too badly 

 preserved to determine the species, or even to determine whe- 

 ther or not it belong to any species now existing. 



In the neighbourhood of Aix, in Provence, some remains were 

 found in 1779, which the Baron, with good reason, refers to 

 the sub-genus of the land-tortoises. The figures given of them 

 by M. Lamanon, in the " Journal de Physique," are, it is true, 

 very imperfect ; but there can be no doubt of their having be- 

 longed to the genus of tortoises, and the very convex figure of 

 the carapace leads infallibly to the conclusion that they must 

 be referred to the sub-genus we have mentioned. They were 

 at first taken for human heads. Guettard iipagined them to 

 be nautili. Lamanon was the first who recognized them to be 

 what they really are. All the laminae and sutures did not ap- 

 pear in the petrified tortoise, until what remained of the shell 

 had been removed. The substance of the stone, while it was 

 yet soft, had taken the place of the animal, and formed a 

 mould, over which all the parts of the shell were clearly to be 

 distinguished. Eight ribs remained on each side very much 

 curved, and came to an end at the vertebral plates, which are 

 arranged longitudinally, and separated by a tolerably deep fur- 

 row. This is the description of M. Lamanon ; but the furrow 

 was caused by the projection of the body being imprinted con- 

 cavely on the mould. The writer in question adds a charac- 

 ter, which, united to the great convexity of the carapace, 

 proves that those remains must have belonged to the land- 

 tortoise. This is, that the laminae are not of equal breadth 

 throughout their whole length ; they go on growing more nar- 

 row, and are emboxed into each other, so that after a base 

 comes a summit, and so on. This is an exclusive charac- 



