198 DR. C. J. rORSYTII MA..TOR ON MIOCENE SQUIRRELS. [Feb. 2'^, 



pronounced unfavourably on the theory since it was first brought 

 forth, and the same is the case, so far as I am aware, \\ ith biologists 



in general. 



The cardinal point established, to use Osboru's words, is that 

 " the aatero-external cusxj in the lower molars and the antero-internal 

 cusp in the upper molars of the Mammalia are homologous u'ith the 

 reptilian cone and tvith each other '". 



Trituberculism, or, as we rather ought to call it, the reptihan- 

 cone theory, is no more a theory, but luis become a dogma. I am 

 a heretic, "and may say that I opposed the theory already in 

 1873, viz. before it was invented"; since that time I have kept 

 silent for various reasons. 



My intention is not to deal fully with the subject on this 

 occasion ; 1 wish only to present a few general remarks on what I 

 consider to be weak points of the theory, and then to enter on 

 more particulars so far as the Sciurine type of molars is con- 

 cerned. 



It is but fair to begin with the Puerco fauna, the stronghold of 

 trituberculism, from the discovery of which dates the estabhshment 

 of the theory. In this fauna we have 106 species of Vertebrates ', 

 the most numerous being the Condylarthra with 23, and the 

 Creodonta with 50 species '. I have already stated that, according 

 to Cope, amongst 82 Puerco Mammalia only four are quadrituber- 

 culate, all the rest being trituberculate. 



Now it appears to me that the Puerco fauna, as at present 



known, does not give us an adequate idea of what must have been 



the Mammalian life of that period, the proportion of caruiAorous 



Mammalia being far too large to be a real one. So that we meet 



here with exactly the same mode of argument which years before 



had been resorted to \\ith regard to the zygodont type. In the 



oldest (then weU-known) Tertiary Mannnalian faunas the Lophio- 



dontid*, showing a relatively simple type of molar, « ere richly 



represented ; hence it was concluded that this ^^ as the primitive 



type of the ungulate molar, lliitimeyer has recently strongly 



insisted upon the fact that the Carnivorous Mammaha of the 



Eo-erkingen fauna, the same whicli has yielded numerous remains 



of Lo]ihiodontid8e, are exceedingly poorly represented, the remains 



of Ungulata being more than twenty times in excess of those of 



Carnivora'. In the Puerco, on the other hand, where we have 



an analogy to the Egerkingen" fauna in regard to primitive types, 



1 Osborn and Wortman, " Fossil Mammals of the Wahsatch and Wind EiTer 

 Beds, Collection of 1891," Extr. from Bulletin of the American Museum of 

 Nat. Hist. iv. no. 1, Oct. 1892, p. 85. 



^ Forsyth Major, " Nageriiberreste aus Bohnerzen Siiddeutschlands xuid der 

 Schweiz. Nebst Beitriigen zu einer vergleichenden Odoiitogvaphie von Ungu- 

 laten und Unguiculaten," 1873. Palseontwgrapliit-a, sxii. 



'■' Cope, ' Synopsis Puerco Fauna,' p. 300. 



' Id. ib. pp. 304, 30.5. 



' L. Kiitimeyer, " Die Eocane Saugethierwelt von Egerkingen," Abband- 

 lungen d. schweiz. paliiontol, Ges. vol. xviii. 1891, p. 93, 



^ Eiitimeyer, ih. 



