13 



Aufsätze. 



Extra Cusps on the Human Teeth. 



By B. C. A. Windle, M, A., Mid. Prof, of Anatomy Queen's Coll. Bir- 

 mingham, and J. HuMPHEBYs, L. D. S. I. Lecturer on Dental Anatomy 

 and Physiology in the same College. 



5 Fig. 



Scattered throughout odontological literature are to befound refe- 

 rences, though scanty in number and substance, to cusps beyond those 

 usually recognised , occurring on the human teeth. These cusps be- 

 come of greater interest than woned appear from the attention which 

 has been paid to them, when studied in connection with the teeth of 

 other Mammals in which they exist of greater size and importance. 

 This paper is designed to give an account of such extra cusps as 

 have been met with by ourselves in the examination of Human Teeth, 

 with some remarks upon their relation to cusps in the teeth of other 

 Mammals. 



Molars. The first upper molar has not uncommonly an addi- 

 tional cusp attached to the lingual side of the antero-internal cusp 



Fig. I. 



(Fig. I« 5. — Fig. II d. — Fig. Ill ft- — Fig. IV ff). It is very 

 distinctly separated from the rest by a groove which opens into that 

 separating the postero- and antero-internal cusps and is of almost 

 equal size to the latter. Where present the crown is quinqui- instead 

 of quadri-cuspid. This cusp is sometimes found on the second molar 

 though not in so well-marked a condition; never, so far as we are 

 aware, on the third. In some cases it hardly rises to the dignity of 

 a cusp, being little more than an elevation of the cingulum exten- 



