THE SUPPOSED FOSSIL DIDELPIIIS. 51 



the marsupials does not appear to him so evident ; that the 

 teeth are more like those of the Insectivora, and that they also 

 bear some resemblance to those of the seals. From this then 

 it appears that the claim of M. Agassiz can relate only to the 

 erroneously supposed relation of these fossil remains to the 

 opossums, and to a certain resemblance of the posterior molars 

 to those of many species of seal. I therefore very willingly 

 repeat what I said in my first " Doubts," and which I learned 

 from M. de Roissy, that M. Agassiz had told him that he had 

 printed in a note added to the German translation of Prof. 

 Buckland's work on Geology and Mineralogy, that the fossil 

 bones of Stonesfield did not belong to a mammiferous animal. 

 To this M. de Roissy added that he knew from another source, 

 and not from M. Agassiz, as I erroneously remarked in my 

 first "doutes," that Dr. Grant, the Professor of Comparative 

 Anatomy at the London University, had advanced the same 

 opinion in his course of Lectures this year, at the same time 

 assigning his reasons for it. 



But as I have been able myself to consult the first article 

 quoted above, in M. Leonhard's Journal, and the second in 

 the German translation of Dr. Buckland's work, of which, 

 however, a part only has recently arrived in Paris ; — I think 

 it requisite for me to give my own literal translation of it, in 

 order that I may be able to notice some inaccuracies which 

 have escaped M. Valenciennes. 



In the first place let us consider the first note. 



"As to the enigmatical species of Didelphis from Stones- 

 field," says M. Agassiz, " I now know that it is not a fish. — 

 I have seen all the specimens which are in the English col- 

 lections, — five lower half jaws belonging to two species, — but 

 nowhere any trace of vertebra, or of bones of the extremities. 

 The trenchant crown of the largest molars, laterally com- 

 pressed, always has two small notches on each side, and con- 

 sequently five pointed tubercles. The smaller ones have but 

 three ; they are certainly those of mammals ; but that they 

 may be compared with the teeth of the marsupials, is not the 

 case. The dental system indeed has also much resemblance 

 to that of the Insectivora, and each separate tooth resembles 

 even the greater part of those of the seals, near which group 

 the animal to which these jaws belonged should form a dis- 

 tinct genus. In fact the aspect of these fossil fragments is so 

 peculiar, that it draws our attention towards aquatic animals 

 rather than away from them." — * (Neue Jahrbuch Mineral, und 

 Geolog. von Leonhard und Bronn, 1835; torn, iii., p. 185; 

 in a letter written from Neufchatel, Switzerland, June 20th, 

 1835.) 



