ON THE MALLEUS OF THE LACERTILIA, ETC. 579 



On the Malleus of the Lacertilia, and the Malar 

 and Quadrate Bones of Mammalia. 



By 



IW. I.. ]>ollo, 



Assistant-Naturalist in the Royal Museum of Natural History, Brussels. 



Witli Plate XLI. 



The apparent absence of a quadrate bone in Mammals has 

 given rise to a large number of theories, differing in details, but 

 all, or nearly all, tending to discover this bone in the chain of 

 ossicula auditus of these animals. A recent work, published 

 by my friend Professor P. Albrecht,^ departs, however, from 

 the view ordinarily taken, and, as I believe, advances our 

 knowledge considerably on the subject. I have been led by 

 the study of this memoir to a discovery which I believe to be 

 of considerable interest, of which it is the object of the present 

 communication to give an account. 



Before passing to the consideration of my own observations 

 I will briefly review the state of the question. This cannot be 

 better accomplished than by reproducing the excellent recapi- 

 tulative tables given by M. Albrecht. 



' P. Albrecht, " Sur la valeur morphologique de rarticulation maudibulaire, 

 du cjirtilage de Meckel et des Osselets de Touie, avec essai de prouver que 

 recaille du temporal des Mammifiirs est composee primitivemeut d'uu squa- 

 mosal et d'un quadratum '" (Mayolez, Bruxelles, 1883). 



