398 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Juiie 23, 



They are found in the ^ Annales du Museum d'Histoire Naturelle/ 

 t. xii. article iv. pp. 88-101 (Paris, 1808), and in the ' Ossemens 

 Fossiles,' t. V. partie ii. article iv. p. 143 (5th ed., Paris, 1826). 



In a collection of fossil bones from the neighbourhood of Honfleur, 

 made by the Abbe Bachelet, and afterwards transferred to the 

 Museum of Natural History, Paris, Cuvier recognized parts of the 

 upper and lower jaws of two species of Gavials, differing from all 

 recent and extinct ones then known, and also vertebrae of two kinds. 

 The least-mutilated lower jaw comprised the entire dentary por- 

 tion, with the greater part of both rami. The composite character 

 of the jaw, its teeth, and the manner of their implantation and of 

 their succession demonstrated the crocodilian nature of the fossil. 

 In its long symphysis and in the restriction of the teeth to this part 

 of the dentary bone, Cuvier saw resemblances to the Gavial ; but 

 he also perceived that the Honfleur Gavial differed from the Gange- 

 tic in the relatively greater length of the ramus, in the smaller 

 angle included by the rami at the symphysis, in the more regularly 

 tapering form of the head, and in the absence of the oval hole pre- 

 sent in the outer surface of all known living crocodiles. Cuvier 

 does not give a very detailed account of the teeth ; but he mentions 

 that they are conical and striated, and have '*deux aretes tran- 

 chantes." (Pigs. 1 & 2, pi. viii. Oss. Poss., are upper and side views 

 of this lower jaw.) 



To this lower jaw Cuvier confidently allotted the fragment of an 

 upper jaw comprising the symphysis with part of both intermaxil- 

 laries containing three alveoli and forming the front of the external 

 nostril. (Pigs. 6 & 7, pi. viii., are upper and under views of this fos- 

 sil.) 



Cuvier's lower jaw wants the posterior extremities of the rami, 

 while from the Kimmeridge jaw the middle of the dentary piece is 

 absent. A comparison of its measurements with those of the Hon- 

 fleur jaw given by Cuvier is therefore not possible; but in all the 

 points in which a comparison can be instituted, the resemblance be- 

 tween the Kimmeridge and the Honfleur jaw is very close. 



The Kimmeridge lower jaw, like the Honfleur (tete a museau 

 plus court), has also a very long non-tooth-bearing ramus, which in- 

 cludes a larger angle with the straight tooth-bearing symphysis 

 than does the living Gavial's ; and this makes a sharper mandibular 

 arch, indicative of a more uniformly tapering head, than the Gavial's. 

 It also has not the oval hole in the outer surface which we find in 

 all living crocodiles, and in all those, I think, of the Tertiary period. 

 Its teeth, too, are conical, (very finely) striated, and they have " deux 

 aretes tranchantes." 



Next, the likeness of Cuvier's upper view of the fragment of the 

 maxilla of the " tete a museau plus court " (fig. 6, pi. viii. ' Osse- 

 men'sPoss.') to the corresponding view of the same part of the upper 

 jaw of this Kimmeridge crocodilian is so striking that it is impossible 

 not to recognize it. 



This Honfieur fragment is very remarkable from the absence of 

 bulging, and from the lateral compression of its terminal nostril. 



