200 DB. C. J. FOESYTH MAJOR OK MIOCEKE SQriREELS. [Fel). 28, 



seems to be coming to me from the very side from \vliich it was 

 least expected. 



Schlosser in liis turn has, in his elaborate and valuable Mono- 

 graphs \ taken trituberculism as his guide for tracing the phylogeny 

 of various orders of Mammalia. He states his ground to be as 

 follows : — " AVe have but to start from the perfectly recognized 

 primitive type and to trace the modifications which it has under- 

 gone"". This perfectly recognized primitive type is, according to 

 Schlosser, the tritubercular type of upper molars, and the tuber- 

 culo-sectorial type of lower molars. Accordingly, in the diagram 

 placed by him at the head of the Monograph of Carnivora ^ this form 

 of molar type is attributed to the supposed first true Carnivore. 



In accordance with the theory, Schlosser considers Mesonycc 

 or Sarcothraustes to be the primitive type of Carnivora '. With the 

 same inexorable logic all Ungidates are derived from carnivorous 

 Mammalia ; the Condylavthra being considered as intermediate 

 between the Ungulata and Creodonta\ 



I have not to deal with Carnivora on this occasion, so that I w ill 

 only mention incidentally that, in my eyes, amongst recent Car- 

 nivoi-a, the Subursi (and, so far as the form of molars is concerned, 

 Ailurits) approach nearest to the primitive carnivorous Mammalia, 

 whilst some of the Arctocyonidae are the most primitive of Creo- 

 donta. 



Further objections may be made when Schlosser considers with 

 Cope a rather complicated form of inferior molar — the tuberculo- 

 sectorial type — to be a primitive form, and when it is assumed that, 

 whilst the upper molars become further modified by addition, the 

 lower molars from quinquetubercular become quadritubercular in 

 progress of time, by the loss of an anterior cusp, the paraconid. 

 The tuberculosectorial type is, in its turn, derived from a simpler 



1 M. Scblosser, " Beitriige zur Keuutniss der Staimuesgeschiebte der Hiif 

 thiere uiid Versuch einer Systematik der Paar- und Tjiipaarhufer," Morpbolog. 

 Jahrbufh.xii. 1887, pp. l-loO ; — ul. "Die Affen. Lemiireu, Cbiropteren, Insecti- 

 voren, Mai'siipialier, Creodonten und Carnivoren des europaiscben Tertiars 

 und deren Beziebungen zu ibren lebenden und fossilen aussereuropaiscben 

 Verwaudten," I.-III., Wien, 1887-1890 (Beitriige z. Paliiontologie Oesterreich- 

 Ungarns, Bd. vi.-viii.) ; — id. " Ueber die Beziebungen der ausgestorbenen Sauge- 

 thierfauuen und ibr Ycrbiiltniss zur Saugetbierfauna der Gegenwart," Biolog- 

 isclies Centralblatl, Bd. viii. no. 19, Dee. 1888, pp. 582-G31. 



- " Es bandelt sicb inir daruin, von dera woblerkanuteu Grundtypus auszu- 

 geben und alle Veranderungen zu verfolgen, welcher derselbe fiihig ist," Die 

 Affen, &c. ii, p. 9 (233). 



^ Id. ih. p. 4 (228). 



■* " Wenu wir von der Voraussetzung ausgehen — und biezu sind wir audi 

 Tollauf bereobtigt— dass der Oberkiefcr-Molar der Creodonta urspriiuglicb den 

 Tritiiberculartypus iu vollster Eeinbeit gezeigt liabe, so niiissen wir Me.<oiit/,r 

 oder Sarcofhrausfrs unbedingt als den Vrtvpus betracbten, wenigstens tui- jene 

 Formen, deren obere Molaren mit riiiid/ichcii Hc'ickern verselien sind. Ea 

 sebliessen sicb diese Typen niebr an die Raubbeutler als an Didclphi/n an," 

 Die Affen, Lenniren, etc. i. p. 1(U. 



" ". . . 68 kann keinem Zweifel unterliegen, dass alle Hufthiere Ton Fleisch- 

 fressern abstammen, wobei cben die Coudylartluen das Zwischenstadinm 

 repriisentireu " — M. Schlosser, Ausgestorbeue Siiugethierformen, /. c. \t, 585. 



