152 



eleven. The crowns are incurved, faceted externally, and striate grooved 

 internally ; there are cutting-edges in front and rear, both strongest near the 

 apex ; the anterior continued to the base, the posterior wanting on the basal third 

 on the median maxillaries. The anterior nareal excavation marks the fourth 

 tooth from the premaxillary suture. The premaxillary bone is remarkable for 

 its shortness and flatness at the extremity ; this part being depressed and 

 scarcely projecting at the lower margin in front of the anterior teeth. These, 

 as usual, number four. 



Both quadrate bones are preserved nearly entire. They have the same 

 general character as those of PI. ictericus and PL coryphceus ; resembling rather 

 the latter in the great length of the posterior hook, which is without posterior 

 marginal button. The proximal internal angle. is large and obtuse, and is 

 continued into a prominent thick ridge. The latter divides below, the thick 

 extremity turning outward and ceasing; an acute ridge continuing inward, and 

 joining the interior acute extremity of the distal articular surface. The sub- 

 meatal knob is broad and thick, and not prominent; and its extremity turns at 

 an acute angle forward on the outer face, and forms the commencement 

 of the great ala. The articular surface is straight crescentic, with an expan- 

 sion on a tuberosity on the inner face (concave of crescent). The meatal pit 

 is sunk between the ridges surrounding, one of which is on the outer margin 

 of the posterior hook. 



The mandible is nearly perfect. The dentary bone bears thirteen teeth, 



and, at the extremity, is contracted in both directions, and not prolonged beyond 



the base of the last tooth. The ridge, which descends from the cotylus along 



the inner face of the articular bone, is not nearly so strong as in the P. 



in udgei. 



Measurements. 



M. 



Length of the axis with the odontoid 0. 0(32 



Elevation of t lie neural spine of the odontoid at the middle 0. 04(3 



Length of the third cervical (hody) 0.050 



Diameter of the ball, vertical 0. 025 



Diameter of the ball, horizontal 0. 03'J 



Length of a posterior dorsal 0. 0(i. r > 



Diameter of the ball, vertical 0. 038 



Diameter of the ball, horizontal 0. 030 



Length of the basis cranii 0. 0B0 



Length of the suspensorium 0. 105 



Elevation cf the occipital crest above the floor of the foramen magnum 0.015 



Length of the tooth-line of the palatine 0. 1 15 



Length of the maxillary bone 0. £10 



Length of the premaxillary laterally 0. 0.15 



