806 THE WHITE RIVER FAUNA. 



pressed crest does not project abruptly, but exhibits a muscular insertion 

 some distance below the head. 



The edges of the outer lobes of the first superior molar are acute ; 

 there is no external cingulum, but the diagonal crest from the median cusp 

 passes to the posterior base of the posterior outer. There is a short but strong 

 cingulum on the posterior base of the median lobe, which terminates in a small 

 internal cusp. The rudimental anterior middle cusp is on the anterior diag- 

 onal ridge, which does not reach the base of the outer anterior cusp. The 

 outer cusp of the last premolar is elongate and compressed ; the inner cusp 

 is small, acute, and opposite the posterior margin of the outer; enamel 

 smooth. The anterior of the two prisms composing the inferior true molars 

 is more elevated than the posterior. The crests of each form a V with the 

 obtuse apex outward, and the anterior limb is shorter than the posterior. 

 The last molar is a little smaller, and is produced behind by the addition of 

 a small median lobe. In the last premolar, the conic cusps are well sepa- 

 rated, and the inner one of the heel is insignificant. This tooth appears to 

 have been the last one protruded; its temporary predecessor is distinguished 

 by the obtuseness of the cusps, especially of the anterior one. Mandibular 

 ramus deep, compressed, without inferior hook as far as opposite the basis 

 of the coronoid process. 



Measurements. 



M. 



Lengtli of sectorial and two tuberculars 0.0210 



Length of sectorial alone - 0045 



Width of sectorial 0020 



Width of first tubercular 0030 



Length of first tubercular 0032 



Depth of jaw at first tubercular - 0060 



Width of skull behind 026 



Length from occipital condyle to postglenoid process 013 



Length of basioccipital 006 



Width of basioccipital medially 005 



Transverse extent of postglenoid process 006 



Length of two centra, third and fourth cervical vertebrae 007 



Transverse extent of fourth cervical between parapophyses 012 



„. ^ c i V, V J < transverse 006 



Diameter of centrum behind ^ 



< vertical 003 



Total elevation fourth cervical 0066 



Total length of axis 007 



Length of odontoid process 0025 



^ ^, ^ . , < vertical 0090 



Diameter of atlas anteriorly < . 



( transverse 0140 



