474 BAUR. [Vot. III. 
quadratojugal. In the Geckonidz generally only one bone is 
present ; this represents the quadratojugal, the squamosal may 
be lost entirely or reduced to a diminutive scale. In the Cha- 
mzeleontide the quadratojugal has been greatly enlarged at the 
expense of the squamosal, which has been almost entirely re- 
duced. In the Rhynchocephalia (Sphenodontidz) and Chamee- 
leontidz we have the two extremes of development of these two 
elements. In Sphenodon the squamosal is very large, the quad- 
ratojugal very small; in Chameleon, the quadratojugal is very 
large, the squamosal very small. 
In the Plesiosauria, Theromora, and Mammalia, the quadrato- 
jugal and squamosal are confluent with the quadrate. 
Sept. 15, 1889. 
