1890.] DENTAL ABNORMALITIES. 3/7 



upper molar on one side and 5 cases of an additional upper molar 

 on both sides. 



I have found the following abnormalities in skulls at the British 

 Museum : — 



C. magellanicus, No. 46. 11.3. 9 : an extra lower molar on both 

 sides. 



C. lateralis. No. 71. 5. 27. 8: five premolars on the right side. 

 One of these is an extra tooth introduced between P. 1 and P. 2, as 

 is shown by the presence of a corresponding diastema on the left 

 side. 



C cancrivorus, No. 10336: a small extra lower molar on both sides. 



In No. 46. 6. 15. 3, on the right side of the mandible there is, 

 instead of the third lower molar, a bunch of five small denticles, as 

 shown in the accompanying figure. 



Hindmost teeth of right side of mandible of a specimen of Canis cancrivorus. 

 Twice the size of nature. 



In skull No. 84.2. 21. 1 there is a very small extra lower molar 

 on one side. 



In Cyon javanicus. No. 58. 5. 4. 99, the second upper molar is 

 wanting on both sides. 



Professor Huxley has noted ' the abnormalities above given as 

 regards C. magellanicus and C. cancrivorus, including the five small 

 denticles. He has also called attention to a South-American canine 

 skull described by Van der Hoeven as having an extra upper molar 



' lu his papers on the Canidts, P. Z. S. 1880, p. 268. 



