146 The American Nairn 



quadrat?. The paroccipital even does not touch the quadrate, but is 

 connected by the anterior and upper portion of its distal process with 

 the inner side of the squamosal ; the face of the distal end of the par- 

 occipital is entirely free from any connection and is always visible 

 from the outside. The paroccipital process is placed behind and also 

 above the upper face of the quadrate for these elements. In none of 

 the genera mentioned above I find a face on the paroccipital for the 

 quadrate, but a face for the squamosal. In the Mosasauridse I find 

 the same. The quadrate is supported by the squamosal and the squa- 

 mosal is connected by its inner process with the anterior face of the 

 distal end of the paroccipital ; the prosquamosal takes also part in the 

 support of the quadrate. We have, therefore, the same conditions as 

 in the genera mentioned. The statement that the Mosasauridse agree 

 with the Ophidia in the relations of the quadrate, is absolutely incor- 

 rect. — G. Baur, University of Chicago. 



Explanation of Figures. 

 Fig. 1. — Conolophus subcristatus Gray. Left quadrate and its rela- 

 tione v squamosal and paroccipital, from 

 behind. 

 Fig. 2. — Conolophus subcristatus Gray. Left quadrate and its rela 

 tions to the squamosal, prosquamosal and paroccipital, from 

 outside and little behind. 

 Fig. 3. — Conolophus .-■uberl.-hitu* Gray. Right quadrate and its rela 

 tions to the squamosal and prosquamosal. from behind and a 

 little inside. 

 Fig. A.— Conolophus subcristatus Gray. Right quadrate and its rela- 

 tions to the squamosal and prosquamosal, from behind, 

 q- Quadrate. 

 ep=Epiphysis of quadrate. 



sq=Squamosal (mastoidien, Cuvier ; opisthotic, Cope, 1870 ; paroc- 

 cipital, Cope, 1892-95). 



psq= Prosquamosal (temporal, Cuvier; squamosal Cope, 1870; 

 supratemporai, Cope, 1892-95). (Baur, G. Anat. Anz. Bd., X, p. 

 .327.) 



p= lateral process of parietals. 

 po= paroccipital (exoceipital, Cope). 

 dpo— distal end of paroccipital. 



