THE MAGAZINE 



OF 



NATURAL HISTORY. 



MAY, 1839. 



Art. I. — Extracts from the Proceedings of the Geological Society 

 of London, relating to the supposed Mammiferous Remains of the 

 Stonesfield Oolitic Strata. ' 



" Nov. 21, 1838.— A paper was first read J On the jaws of the Thylacothe- 

 rium Prevostii (Valenciennes) from Stonesfield,' by Richard Owen, Esq., 

 F.G.S., Hunterian Professor, Royal College of Surgeons. 



" Doubts having been recently expressed by M. de Blainville, from in- 

 spection of casts, respecting the mammiferous nature of the fossil jaws found 

 at Stonesfield, and assigned to the Marsupialia by Baron Cuvier, Mr. Owen 

 brought the paper before the Society to meet the objections, and to give a 

 detailed account of the fossils from a careful inspection of the originals. — 

 In this communication, however, he confined his description chiefly to the 

 jaws of one of the two genera which have been discovered at Stonesfield, 

 and characterised by having eleven molars in each ramus of the lower jaw, 

 reserving to a future occasion an account of the remains of the other genus. 



" Mr. Owen commences by observing that the scientific world possesses 

 ample experience of the truth and tact with which the illustrious Cuvier 

 formed his judgments of the affinities of an extinct animal from the in- 

 spection of a fossil fragment ; and that it is only when so distinguished a 

 comparative anatomist as M. de Blainville questions the determinations, 

 that it becomes the duty of those who possess the means, to investigate the 

 nature of the doubts, and reassure the confidence of geologists in their 

 great guide. 



" When Cuvier first hastily examined at Oxford, in 1818, one of the 

 jaws described in this paper, in the possession of Dr. Buckland, he decided 

 that it was allied to the Didelphys, (me semblerent de quelque didelphe 2 ) ; 

 and when doubts were raised by M. Constant Prevost, in 1824 3 , relative to 

 the age of the Stonesfield slate, Cuvier, from an examination of a drawing 

 made for the express purpose, was confirmed in his former determination ; 

 but he added, that the jaw differs from that of all known carnivorous Mam- 

 malia, in having ten molars in a series in the lower jaw: "il [the drawing] 

 me confirme dans l'idee que la premiere inspection m'en avoit donnee. — 



1 For other papers upon this subject by M.M. De Blainville and Valen- 

 ciennes, see ' Mag. Nat. Hist.' vol. ii. n. s., p. 639, and vol. iii. pp. 1 & 49. 

 2 'Ossemens Foss.' tome iii. p. 349. 



3 'Annales des Sciences Nat.' Avril, 1825 ; also the papers of Mr. Bro- 

 derip and Dr. Fitton in the Zoological Journal, 1828, vol. iii. p. 409. 



Vol. III.— No. 29. n. s. y 



