ART. 553. 



AN EXTINCT VAEANID LIZARD GILMOEE. 



11 



Fig. 10. — Left pre- 

 frontal OF Saniwa 



ENSIDBNS LeIDY. 



Type, Cat. No. 2185, 

 U.S.N.M. Natural 



SIZE. la, SURFACE 

 FOR ARTICULATION 



FOR lachrymal; 



prf, FRONTAL BORDER. 



nated at about the center of the orbit. The anterior extension of 

 this bone is missing. A decidedly roughened ridge is developed 

 along the angle where it turns downward to fonn the lateral surface. 

 This ridge probably marks the seat of attachment for the supra- 

 orbital bone, which is missing in this specimen. On the ventral 

 part of the lateral surface there is an indented articular area, which 

 marks the point of articulation with the separate 

 lachrymal bone. Posterior to the lachrymal ar- 

 ticulation the bone turns inward, forming a widv-^ 

 contribution to the anterior border of the orbit. 

 The ventral edge of this orbital portion is slightly 

 expanded anteroposteriorly for articulation with 

 the underlying palatine, to which it is joined in 

 the articulated skull. Anteriorly it appears to 

 have articulated w^ith the maxillary as in Vara- 

 nus. It probably was also in contact with the 

 nasal, but of this I am not entirely certain. 



Quadrate. — The complete left quadrate shows 

 this element in its general characteristics to 

 closely resemble the corresponding bone in the Varanus skull. It is 

 a strong bone of moderate length, having a wide articular end for 

 articulation of the lower mandible. This end has a transverse width 

 of 8 mm. Viewed from the side, the quadrate is narrow anteropos- 

 teriorly at the lower end but rapidly widens in the same diameter 



Q^ toward the proximal end. This 

 widening is brought about by the 

 inner half of the bone being inclined 

 strongly backv.ard from the perpen- 

 dicular. The upper articular end of 

 the inner portion rises considerabW 

 above the upper extremity of the 

 outer portion of the bone. In the 

 articulated skull it is presumed that 

 the inner articulated with the supra- 

 temporal, squamosal, and paraoc- 

 cipitat bones as in Varanus. The 

 outer half of the quadrate measures 

 15 mm. in length; the inner. 18 mm. On the inner side of the distal 

 end a flattened facet evidently marks the place of contact with the 

 posterior extremity of the pterj^goid. 



Jugal. — A long curved bone is provisionally identified as the left 

 jugal. If this determination is correct it shows this bone to be 

 considerably more robust than the jugal in a Varanus skull of equal 

 dimensions (see fig, 1). The pointed posterior extremity is miss- 



FiG. 11. — Left jugal of Saniwa bn- 

 siDENS Lbidy. Type, Cat. No. 

 2185, U.S.N.M. Natural size. A, 

 internal view ; B, external view ; 

 a, anterior end ; p, posterior end. 



