1821.1 Lactrla Gigantea of the Ancient World. 187 



is obviously unlike. No tooth, for instance, has a crown termi- 

 nating in several points, as is the case with almost every one of 

 the lacerta monitor, but each adheres to the jaws by a swelling, 

 flatly rounded root, has a pyramidal top somewhat inclined tor- 

 wards and is coated with a brownish enamel. The root or 

 kernel of these teeth differ as well by their less dark, bright grey 

 colour, as by their greater thickness, not only from the substance 

 of all the other bones, but even from that of the jaw. 



The top, which is covered with a brown, dark, porcelain spe- 

 cies of enamel, has almost the appearance of a dagger. The 

 exterior surface of this part of the tooth is divided from the inner 

 one by a dark, sharp, jagged edge (almost the same as in the 

 <rlossopeter); and is not only less convex than the inner surface, 

 but has moreover obtuse-angled facettes in its longitudinal direc- 

 tion. In order to exhibit this more distinctly, I have given a 

 magnified representation of the best preserved of these teeth 

 both the external face, fig. 4 ; and a section through it, fig. 7. 



In both the sculls of tupinambis, with which I have been 

 favoured by the kindness of Prof. Schneider, of Breslaw, I find 

 similarly formed teeth, only in these the dark jagged angles are 

 not easily discernible without a magnifying glass. This resem- 

 blance between the teeth of our unknown animal and those ot 

 the tupinambis warrants us in assigning it to the genus lacerta?. 

 As far as I can form an opinion from the teeth ot the Maas- 

 tricht animal ;* from those which I formerly possessed myself, 

 afterwards given to M. Ebell, of Bremen; and from others ot 

 them which I saw in the possession of ray distinguished teacher, 

 Petrus Camper ;f— from his masterly representations of the same, 



from those in the works of his son Adrian Camper,;}: Faujas St. 



Fond,^ or Cuvier,|| the teeth of our incognitum bear the most 



• In speaking of the Maestricht animal, Cuvier terms this solid part of the tooth not 

 the root but the kernel (noyau).— (Ann. du Mus. torn. xn. p. 156.) 



t This eminent naturalist gave a most admirable representation of the teeth of the 

 Maestricht animal, of the natural size, in the Phil. Trans. 1786, vol. 76, PI. 5 and 

 16, p. 446, which has been well copied in his smaller pieces in Heracle s translation, 

 and also copied, but less accurately, in » Les (Euvres de M. Camper, Pans 1803, 

 fol PI. 6 and 7. A better plate of the same subject, though not even this is sufficiently 

 accurate, has been given by Faujas St. Fond, Hist, de la Montaigne de St. Pierre, &c. 



^JournYde Physique, An. ix. 1800, torn. 5., p. 278 PL 1 and2. The size i S 

 less than half the natural dimensions. The hindmost tooth, PI. 2, fig. 6, is the best 



^TltiJtoIre Nat. de la Montagne de St. Pierre a Maestricht, Paris, 1799 ; also in hia 

 J&L de Geologie, Paris, lBOS^Pl. 7. In PI. 4 and 5, of his Iiist.de la Mont, where 

 more than a dozen teeth are exhibited, hardly any one of them is accurately repre- 

 sented. Even in that marked c c, in PI. 49, the root is separated too suddenly from 

 the upper part, and, in most instances, the teeth have the appearance of projecting up 

 from the root as if out of a distinct case. The best representation he has given is PI. 50, 

 fig 1, yet nothing is to be observed of the jagged edge, which is so much he more 

 extraordinary as in the very same plate he has exhibited it very beautifully in the teeth 

 of the shark (squalus), PI. 18, fig. 1 and 9, and as Camper's figure must have pointed it 



OU || Ann. du Mus. d'Hiat. Nat. torn. xii. PI. 19, where the teeth of the Maestricht 

 animal appear as if the root WM contracted just at the commencement of the upper 

 part. 



