Teeth In (he Centetidic. !)'dl 



from it. To his question, " Why may not Ifyienodon and 

 l*tero(lon be an extreme development of that type of the 

 Insectivora whicli is at present represented by Centetes?" 

 \Vii)go* returned the categorical answer, " Because n>/(cno<Ion 

 and Pterodon have not in the slightest degree a special 

 resemblance to Insectivora, least of all to Centeles ; there is 

 not one single point in which Centetes does not stand in sharp 

 contrast to Hineuodon and the Carnivora." Winge then 

 proceeds to develop this view by interpreting the upper 

 molars of Centetes in the following manner : — " The hindmost 

 of the three outermost cusps has disap))eared," he writes, " as 

 also the posterior of the two that immediately follow these on 

 the inner side ; on the other hand, the anterior two of the 

 original three outer cusps and the anterior of the two that 

 immediately follow these are still ])resent in a particularly 

 well-developed form ; we also observe remnants of a single 

 talon, which in other Centctida? is well developed." Conse- 

 quently in the interpretation of the homologies Winge agrees 

 in the main with Mivart. 



I have shown in an accurately-drawn figure of an upper 

 M. 1 of Centetes f that in a perfect condition this tooth, like 

 that of Potamogale, possesses not less than five outer cusps ; 

 it is true that two of these are more strongly developed than 

 the rest. In the figure in question I distinguished the main 

 cusp of the tooth, situated on the inner side of those just 

 referred to, by the numbers 4 + 6, in order to indicate thereby 

 that in Centetes there seems to have taken place a fusion of 

 the inner talon — 6 in Winge's figures and diagrams — with 

 the main cusp, Winge's 4. 



Cope has recently :j: reasserted his former theory, that in 

 the existing fauna the " tritubercular " form of molar as 

 exhibited by Centetidte, Soricidaj, a few Lemurs, and the 

 majority of the Carnivora is the primitive one. In Centetid^e 

 and Chrysochloridai the rudimentary '' low cingulum " on the 

 posterior base of lower molars and a " posterior cingulum " 

 on upi)er molars are regarded as the first step towards the 

 complication of the tritubercular molars. 



M. F. Woodward § follows Mivart and Winge, since he 

 considers the supposed " paracone " and " metacone " of 

 Centetes and Chrysochhris to be homologous with the " ex- 



* Vidensk. Meddel. fra d. naturh. Foren. i Kjobenhavn, 1882, p. 58. 



t "On Megaladajm niadagascariensis &c,," Phil. Trans. 11. Soc. Lond. 

 vol. 185, 1894, B, p. 23, fig. 4. 



t ' The Primary Factors of Organic Evolution ' (Chicago, 1896), 

 pp. 145, 335. 



§ Proc. Zool. Soc. London, 18J6, pp. 588, 589, and pi. xxvi. 



