156 THE AVASATCFI AND lUMOGER FAUN^. 



fieries, and the last four are short lancet-shaped. The crowns anteriorly 

 are long and acute, but they begin to shorten with the fifth maxillary and 

 diminish regularly posteriorly. Tlie basal portion of a fully protruded 

 crown is smooth; the greater portion is, however, longitudinally grooved. 

 There are eight ridges on the narrower and ten on the larger teeth. The 

 grooves are not so deep, nor the ridges as acute as in C. sulciferus Cope, of 

 the Bridger beds, and the crowns are less robust and not so incurved. The 

 teeth of the present species have more acute edges. On these grounds I 

 have been obliged to regard the C. acer as distinct from the C. sulciferus. 



Measurements. 



M. 



Length of skull to line of extremities of qnadiates ;i90 



Leiii;lli of skull to posterior border of cranial table 345 



Longlb of skull to line of anterior border of orbit 238 



Width of preniaxiUary bones 060 



Width at preuiaxillary notch 046 



Width at fifth maxillary tooth 072 



Width at anterior angle of orbits 058 



AVidtli at posterior border of quadrates 19-J 



Width of iuterorbital space 021 



'-mi., .■ L ■ ^ -ut , < tt'i'iporal foss.-B 090 



Width of po8t<!nor table at < ' , , 



( squamosal angles 126 



Vertical diameter of skull ^ "^'"'"'""^"•"♦''l ''°"'ly'« •^*- 



c below occipital condyle 034 



Width of extremity of osquadratum 033 



Width of posterior nares 014 



Width of inferior orbit 031 



Length of inferior orbit 095 



This species is smaller than the C. affinis, to which it is generally allied. 

 It has a slight trace of the ledge between the anterior borders of the orbits 

 seen in several of the Bridger species. The forms and sculpture of the 

 teeth are entirely different from those of the C. elliottii and allies. In life 

 the species had about the size and form of head of the nairow-nosed caiman 

 now living in South America, Jacare jnmcttdata Natt. 



My only specimen of the CrocodUus acer was obtained by Charles H. 

 Sternberg, from the white limestone near Manti, in central Utah. Other 

 specimens have been subsequently found. This formation belongs to the 

 Eocene period, but its exact relation to those on the east side of the Wasatch 

 Mountains is yet uncertain. I have called it the Manti formation. 



