642 Doubts respecting 



preceding. I have indeed found the minute of my reply, in 

 which I said, that appertaining to a small animal of the sau- 

 rian tribe, rather than to a fish, it appeared certain to me that 

 this fragment could not have belonged to a mammal, whether 

 a Didelphis or not, as I had believed on the first inspection. 



I ought to mention, to speak the truth more fully, that I 

 did not remember having made this reply seven years ago, 

 when a friend of mine, M. de Roissy, to whom I mentioned 

 my last memoir to the Academy, asked me if I should allude 

 in it to the insectivorous mammal of Stonesfield ; and on my 

 replying in the negative, he informed me that M. Agassiz, in 

 his German translation of Dr. Buckland's work on Geology, 

 was about to make mention of an opinion of Professor Grant, 

 that the supposed Didelphis of Stonesfield was not a mam- 

 miferous animal. 



M. Elie de Beaumont, on the occasion of my note to the 

 Academy, informed us that the portion of bone which had 

 been submitted to my examination by M. Brochant de Vil- 

 liers, in 1831, belonged indeed to a reptile, as I had said ; 

 and that this was the opinion of M. G. Cuvier, who had also 

 examined it, and of M. Agassiz ; but that it was quite a dif- 

 ferent thing from the Did. Bucklandii, which was not the less 

 a mammal : so that the fact of the existence of the class 

 mammalia in the oolitic series was not weakened by the above 

 circumstance. 



In the paragraph which M. Elie de Beaumont has added 

 to the extract from my memoir, he indeed says, that having 

 shown to Cuvier the jaw which had been brought to Paris, 

 Cuvier, in pointing out to him the objections to its mammife- 

 rous character, at the same time explained in what respects 

 it differed from the jaw previously found in the same locality, 

 — the Did. Bucklandii. Unfortunately, M. Elie de Beau- 

 mont does not describe these differences ; but they must have 

 been convincing, since M. Agassiz, according to my col- 

 league's information, had given up the idea entertained by 

 Professor Grant, that the jaw was not that of a mammal. — 

 Nevertheless, let us see if, the fragment which I have exa- 

 mined being already referred to the sub-type of oviparous Ver- 

 tebrata, sufficient reasons yet exist for retaining in the class 

 Mammalia the two other fragments found in the same locality. 

 In order that we may judge clearly of this question, let us 

 begin by giving descriptions of these fragments, taken from 

 the authors who have made us acquainted with their history, 

 and particularly from the figures which they have published ; 

 at the same time requesting the parties who possess the ori- 

 ginal specimens, to submit them to a fresh examination. 



