chap, ix.] teeth: canid^e. 217 



size below the normal, having a single root and a crown slightly 

 developed, like that of S This reduced condition of m- may 

 also occur in cases in which m ? is not absent. These observations 

 of Hensel's, which are of great consequence to an appreciation 

 of the nature of Repetition, I can fully attest, and similar cases 

 of Variation in adjacent teeth associated with the presence of a 

 supernumerary were seen in other animals also. 



A. Wild Canid.e. 

 Supernumerary Molars. 



|)4Q_ C. lupus: 26 normals seen. Specimen from Courland having 

 supernumerary ?n? on left. In this specimen «^' is rather ab- 

 normally large on both, sides, and the lower third molar, on the 

 left side, viz. that on which the upper jaw has an extra tooth, is 

 larger than right m 3 , but it is not larger than usual. C. M., 

 976, M. 



Hexsel, I. c, p. 548, saw 27 skulls, none having extra molar, but 

 one specimen known to him had a right n^. 

 t>47. C. mesomelas $ (a Jackal) : small, bitubercular left »»l Doxitz, 

 Sitzb. naturf. Fr. Berlin, 1872, p. 54. (See Nos. 226 and 228.) 



The S. American Ca niche {Lycalopex group) are remarkable 

 for the frequency with which they possess extra molars, as the 

 following cases (C. azarce, vetulus, magellanicus and cancrivorus) 

 testify. Flower and Lydekker 1 speak of the occasional presence 

 of "^ in C. cancrivorus, but the evidence taken together seems 

 rather to shew that there is a general variability at the end of 

 the molar series in both jaws in these species ; for not only is 

 ^ found, but in some cases m* also, while in one instance there 

 was an 'odontome,' or rather a complex of 4 small teeth attached 

 to m 3 . 



;48. C. vetulus, Brazil : specimen having an extra molar in right 

 lower jaw (Fig. 44, 1.). The posterior part of m? is slightly pushed 

 outwards and a very small extra tooth stands behind and partly 

 internal to it. Right m? is slightly larger than left m? and differs 

 from it also a little in pattern. The extra tooth has one large 

 and about three smaller blunt cusps on its crown, and might be 

 described as a small representation of the larger n& seen in other 

 cases. B. M., 84. 2. 21. 1 (mentioned by Mivart' 2 , Monogr. Canidce). 



5 49. Canis azarae : Brazilian specimen having a large super- 

 numerary molar (w 3 ) in each upper jaw placed in series with the 

 others. In this specimen the great enlargement of ^ is very 



1 Mammals, Living and Extinct, 181)1, p. 546. 



- In the same place Mivart mentions a case of "^ in " C. cancrivorus," but I have 

 not seen it. Perhaps this reference is to van der Hoeven's case (No. 24'.)) which was 

 by Burmeister named C. cancrivorus (see Huxley, P. Z. S., 1880, p. 208). 



