170. 



177 



202 



MERISTIC VARIATION. 



[part I. 



not seem to have been broken, but there appears to have been disease 

 of the articulations of the mandibles. B. M., S6, 12, 20, 10. 



Specimen in which "position of the left upper canine is abnormal. 

 It is displaced backwards and lies to the outer side of the first premolar, 

 which it has pushed towards the middle line." C. S. M., 41 (see 

 Catalogue). 



Case in which upper right canine occupies a position within and on 

 a level with the first premolar, which is pushed outwards. C. S. M., 

 40, A. 



Troglodytes niger, calvus, &c. (Chimpanzee). 



Normal adult skulls seen. 35. 



Supernumerary molars. 



*178. Specimen having on right side in upper jaw a very small 

 square tooth behind m*, in the arcade (Fig. 35) ; and in the left upper 



1 



ms 



m 3 V *, 



m 



m.z 



Fig. 35. Posterior right upper molars of Chimpanzee. 



I. The case No. 178 {Coll. Surg. Mus., No. 1). 



II. A normal Chimpanzee of approximately the same size. 



jaw an empty alveolus in the similar place, shewing clearly that 

 a similar tooth has been present : lower jaw normal. C. S. M., 1. 



179. Specimen in which teeth all gone, but alveoli exist behind 

 those of the normal teeth on both sides in upper jaw, and there 

 is little doubt that there was here a fourth molar on each side. 

 C. S. M., 9. 



180. Specimen in which teeth all gone, but alveoli shew clearly that 

 there was a fourth upper molar on right side ; evidence on left 

 side inconclusive : lower jaw gone. C. S. M., 12. 



181. Specimen of T. calvus having an extra mS in lower jaw on 

 right side. This tooth is about one quarter of the size of m z , 

 resembling that in case No. 178. This specimen is in the private 

 collection of Prof. Milne Edwards, who w r as so kind as to shew 

 it to me. 



Gorilla savagei (Gorilla). 

 Normal adult skulls seen, 55. 



