CROCODILIA. 121 



Ladyship has described m the volume of ' Reports of the British Association' above 

 cited, (p. 63). 



When the specimen was originally exposed, it was in the same extremely fragile 

 and crumbling state as the beautiful carapaces of Trionyx obtained by Lady Hastings from 

 the same locality, and described and figured in the chapter Chelonia ; but thanks to the 

 skill and care with which the noble and accomplished discoverer readjusted and cemented 

 the numerous detached fragments of those specimens, the present unique fossil has been 

 in like manner restored as nearly to its original state as is represented in the plates ; 

 and all the requisite characters for determining the nature and affinities of the species, 

 can now be studied wdth the same facility as in the skulls of existing Crocodiles. 



If the reader will compare the plates above cited with the section of Cuvier's 

 ' Ossemens Fossiles,' in which the distinctions between the Alligators and Crocodiles 

 are specified,* he will see, (in fig. 1, PI. 1 S) for example, that the fourth tooth or 

 canine of the lower jaw is not received into a circumscribed cavity of the upper jaw, 

 but is applied to a groove upon the side of the upper jaw, and is exposed. Fig. 1, 

 PI. 1 A, shows that the prefrontal (i4) and lachrymal (73) bones, instead' of descending 

 much less upon the facial part of the skull, extend much more, and advance nearer to 

 the end of the muzzle than in any Alligator, or even than in any actual species of broad- 

 nosed Crocodile. 



The vacuities left between the postfrontal (12), the parietal (7), and the mastoid (s) 

 (PI. 1 A, fig. 1, and PI. 2 B, fig. 3), are as wide as in the skull of a Crocodiiiis biporcatus 

 of equal size, and are larger than in the Alli(/ator Indus or All. sclerops. Fig. 2, PI. 1 B, 

 shows that no part of the vomer is visible between the premaxillaries (22) and maxillaries 

 (21), or elsewhere on the palate. But the palatine expansion of the vomer is not a 

 constant character ; it is wanting, for example, in the Alligator liicius of North America. 

 The palatines (20) are not more advanced in the fossil in question than they are in the 

 true Crocodiles, and their anterior portion does not expand to its anterior truncated 

 termination. The posterior nostril, the entire contour of which is shown in the portion 

 of the skull of the same species figured in PI. 1 A, fig. 3, is longer than it is broad. 



There is but one character in which the fossil skuU in question differs from the 

 true Crocodile, and agrees with most species of Alligator ; it is in the reception of 

 the two anterior teeth of the lower jaw into cavities of the premaxillaries, shown in 



* " Les tetes des caimans, outre le nombre des dents, et surtout la manifere dont la quatrieme d'en bas 

 est recue, outre les differences qui dependent de la circonscriptiou totale, se distinguent de celles des 

 Crocodiles proprement dits, 1°, parce que le frontal anterieur et le lacrynial desceudent bcaucoup moins sur 

 le museau ; 2°, en ce que les trous perces a la face superieure du crane, entrele frontal posterieur, le parietal 

 et le mastoidien, y sont beaucoup plus petits, souvent meme y disparaissent tout-i-fait, comme dans le 

 caiman a paupieres osseuses ; 3°, en ce que Ton aper^oit uue partie du vomer dans le palais, entre les 

 interma.iillaires et les maxillaires ; 4°, en ce que les palatins avancent plus dans ce meme palais, et s'y 

 elargissent en avant; 5°, en ce que les narines posterieures y sont plus larges que lougues, etc." (torn, v, 

 pt. ii, p. 105.) 



