1893.] DB. C. J. FORSYTH MAJOR OX ^IIOCEyE SQnREEIi!?. 203 



menclature) ' more or less transversely united, together m itli 

 Osborn's paraconvl -, and include between them what I ha^e called 

 the anterior transverse valley. Owing to the much-worn con- 

 dition and partly too, perhaps, to the feeble development of this 

 anterior part — as found in some recent Sciuri and in AirtOMi/s — the 

 anterior vaUey has vanished in the fossil molars, though I think that 

 some traces of it are still visible in the first and third molar o£ 

 Scott's figures ', so that, in order to find out the typical triangle, 

 Scott has encroached on what trituberculism declares to be a late 

 addition to the inferior molars, for he considers, as it were, the 

 postero-iuternal cusp, Osborn's entoconid, of the " heel" to be the 

 postero-internal part of the typical triangle. What he calls the 

 talon behind, is but the median cusp {Jufpoconvlid) of Osborn's 

 talon. This hypoconulid is in fact the real " talon," viz. that part 

 Av hich is so generally well developed on the posterior side of third 

 lower molars, but which in many Sciuromorpha can be distinctly 

 made out in the anterior molars too, as well as in milk-teeth of 

 Lepus and Mi/ohr/vs, and both in milk-teeth and permanent molars 

 of Lagodus and Titanomi/f<\ 



The conclusions to be drawn from the foregoing analysis are, 

 I am glad to state, the very same at which Scott has arrived, as 

 they tend to show, e\ en more unmistakably, " that the llodents are to 

 be derived from the same generalized group of ]n'irailiTe placental 

 Mammals, the Bunotheria, to which we refer the origin of the 

 Ungulates, Creodonts, and Lemuroids "''. In respect to what Scott 

 considers plainly to be '•the tritubereular pattern" of superior molars, 

 it cannot be denied that there appear three pi-incipal cusps, two 

 external and one internal one, in the upper molars of Plesiarctonuis 

 sciuroides ; but there are other parts to be seen, even in these mucJi- 

 worn molars, and I have already pointed out that it is dangerous 

 to draw inferences from ivom teeth. 



Very similar remarks apply to tw o papers by Schlosser °, m which 

 this author endeavours to refer the molars of Eodejitia to trituber- 

 cidism. I therefore refrain from discussing them at length, and I 

 wish only to remark upon the second of the papers quoted. Schlosser 

 asserts in the most positive manner, Axhat at first siglit a]ipears to be 

 a startliiig fact, that PJesiadn/ns and Proloadapk, from the Lower 

 Eocene of Eeims, are Eodentia. Flfsiadajrk had pre\ iously been 



' Cf., e. (J., H. F. Osborn aiirl J. L. Wortiuan, " Fossil Mammals of tlie 

 Wahsatch and Wind Kiver Beds." Collection of 1891. L. c. p. 86, figs. 1 & 2. 



'" Bi. 



' L. c. p. 476, and pi. xi. fig. 1 d. 



^ See also the inferior molars oi '■' I'le^iadapls" in Lemoine, "Etude d'en- 

 semble sur les dents des Mammifil-res fossiles des environs de Reims '' (Bull. Soo. 

 Geol. de France, trois. serie. t. xis. Mai 1891, pi. x. fig. ().5 e), and of Dcctica- 

 dapis, ibid. pi. xi. fig. 146 e, 146 es. 



' Scott, I. c. p. 478. 



^ Max Schlosser, " Die Differeuzirung des Saugethiergebisses " (Biol. Centva- 

 blatt, Band x. Nos. 8 & 9, Erlangen, 1 & 15 .June 1890, pp. 2.%, 251).— 7f/. " Ueber 



.Tahrgang 1892, Band ii. p]" 



