166 



Inches. 



Widtb of tbo palatine in front 2.2 



Lcugth of tUe palatine anterior to the transverse process 7.2 



Length of the crown of the fifth pal.atine tooth 1. 



Length of the crown of the second maxillary tooth 1.9 



Diameter of the crown of the second maxillary tooth at the base 1. 1 



The vomers are, as usual, separate and narrow. They are in close contact 

 from the second maxillary to the second premaxillary tooth. Throughout 

 this part of their length, tliey are embraced by posteriorly-produced vertical 

 laminae of the premaxillary bone. These laminae unite anteriorly just behind 

 the second premaxillary teeth, and foi-m a single prominent keel, which disap- 

 pears between the first premaxillaries. 



The fine specimen which is the subject of the preceding description was 

 discovered by Colonel Connyngham and Mr. Minor near Monument Station, 

 Kansas, and sent by them to Professor Agassiz. 



This is the most abundant of the large species of the Kansas chalk. 

 The WTiter found a muzzle consisting of premaxillary and portions of maxil- 

 lary and dentary bones in the spur of the lower bluffs of Butte Creek, and 

 numerous fragments of cranium and vertebrse on a denuded tract in the same 

 neighborhood. Both of these belonged to individuals of smaller size than 

 the type, the opportunity of examimng which I owe to Professor Agassiz. 

 The more complete Butte Creek specimen belongs to a huge animal ; the size 

 is grandly displayed by a complete premaxillary bone, with its projecting 

 snout, and large fragments of the maxillary. These furnish characters con- 

 firmatory of those already given as above. The vertebrse are remarkable 

 examples of flattening under pressure, without fracture ; some of them having 

 a vertical diameter no greater than one's hand. The cervicals are less flat- 

 tened, and give the impression that they were not transversely elliptic. This 

 is consistent with our knowledge of the perfect specimen, where it is, as 

 described, furnished with vertically ovate articular surfaces. In this, the cup 

 is symmetrical and apparently not distorted, but the ball is a little com- 

 pressed by pressure. 



The most important addition to the knowledge of this species furnished 

 by the Butte Creek specimen is the character of the quadrate bone. 



The internal longitudinal angular ridge is very prominent, and extends 

 to the distal end. It supports a hook-like prolongation of the proximal artic- 

 ular surface; almost as large a one as in Clklas/es irrapython, and more nar- 



