THE MALLEUS OF THE LACEETILIA, ETC. 



593 



is not therefore necessary to return to the subject here. Let 

 us study the variations of the two former ; they are compre- 

 hended in the table on page 590. 



Let us now compare the formula given for man with that of 

 Rhynchosuchus Schlegelii. 



Pstfr 



Homo sapiens. 



Rhynchosuchus Schlegelii. 



Only two things are necessary to pass from one to the 

 other, viz. : 



1st. The disjunction of the squamoso-postfrontal arch. 



2nd. The closing together of all the other bones under con- 

 sideration. 



Now, the former condition is very common amongst the 

 Sauropsida. It is to be observed, as has been already stated, 

 in the Ophidians, the Amphisboenidse, the Ascalobotidss, the 

 Chalcidea and Ophidiiform Scinco'idea, the Chelonia, and in 

 Birds ; whilst the latter is by no means rare amongst the 

 Chelonia. 



In short, my explanation of the malar bone of Mammalia 

 avoids entirely the objections raised by M. Albrecht's theory, 

 and exhibits a simple combination of the known phenomena 

 in Lizards : 



Malar = postfrontal + jugal + quadrato-jugal. 



Before resutniug the discussion concerning the quadrate, I 

 may again express my opinion, based on the facts which follow, 

 that — 



1st. The Lacertilia and Ophidia possessed originally an 

 ossified quadrato-jugal. 



2nd. That therefore there existed originally in all the Sau- 

 ropsida a latero-temporal fossa bounded thus : 



