272 MARSTTPIALIA. 



Amphilestes (?) sp. 



This form is of larger size than A. broderipi ; the length of the 

 space occupied by the last four lower true molars being 0,0085, 

 against 0,006 in the latter. 



Hab. Europe (England). 



M. 2300. Cast of a left mandibular ramus, showing the last four 

 true molars. The original was obtained from the Lower 

 Jurassic Slate of Stonesfield, Oxfordshire, and is preserved 

 in the Museum at Oxford. It is figured by Phillips in his 

 'Geology of Oxford and the Valley of the Thames,' 

 p. 235, diagram 81, under the name of PhascolotJierium 

 buMandi ; but the true molars differ from those of that 

 species in the small development of the accessory fore-and- 

 aft cusps, and come nearer in this respect to those of 

 Amphilestes, although the contour of the ramus is more 

 like that of Phascolotherium. 



Presented by Prof. Prestwich, 1885. 



GENUS non. det. 



It. 2299. Cast of a mandibular ramus showing all the teeth, with 

 the exception of the fourth, in a worn or damaged condition. 

 The original was obtained from the Lower Jurassic Slate 

 of StonesMeld, Oxfordshire, and is preserved in the Museum 

 at Oxford. It is figured (under the name of Amphitherium 

 prevosti) by Owen in his ' Odoutography,' pi. xcix. fig. 1, 

 in his ' British Fossil Mammals and Birds,' p. 29, fig. 15, 

 and in his 'British Mesozoic Mammals' (Mon. Pal. 

 Soc.), pi. i. figs. 23, 23 a. It is, however, regarded by 

 Osborn * as decidedly distinct from that form, with molars 

 approximating to those of Amphilestes, but with the 

 cingulum confined to the inner side, and with the condyle 

 pedunculate and placed above the molar level. Owen gives 

 the lower dental formula as I. -, C. - v Pm. ^, M. g, but 

 there appears equal reason for rendering it as I. ^, C. ^ 

 Pm. -, M. -, or the same as in AmblotJierium 2 . 



Presented by Prof. Prestwich, 1885. 



1 See note 1, preceding page. 



2 The superiority in the size of the fourth over the fifth remaining tooth would 

 seem to indicate the probability of the former being a canine rather than a pre- 

 molar ; and that the canine was inserted by two roots is probable from the 

 observations of Marsh, Amer. Journ. ser. 3, vol. xxxiii. p. 335 (1887). 



