40 UINOCERATA. 



The principal dimensions of three of the lower jaws described in this 

 chapter are as follows : 



Measurements of Lower Jaw. {D'uioceras laticeps, No. 1039.) 



m. 



Greatest length of ramus, ... 0.54 



Extent of symphysis, . 0.18 



Height of coronoid process from bottom of ramus, _ . 0.235 



Depth of ramus at last molar, 0.09 



Depth of ramus at tusk process, 0.185 



Extent of diastema, "- _ 0.10 



Extent of molar series, ...._. _.. . 0.18 



Greatest width across condyles, . . .. __ 0.295 



Transverse diameter of condyle, _. 0.087 



Vertical diameter of condyle, — .. 0.048 



Measurements of Lower Jaw. {Uintathfriinu sct/in-. Marsh, No. 1194.) 



m. 



Greatest length of ramus, .. 0.49 



Extent of symphysis, 0. 165 



Height of coronoid process from bottom of ramus (a]iproximate), 0. 1 9 



Depth of ramus at last molar, . - 0.075 



Depth of ramus at tusk process, 0.17 



Extent of molar series (functional),. _ ... 0.145 



Transverse diameter of condyle, 0.076 



Vertical diameter of condyle, ... .... 0.040 



Meastirements of Lower Jaw. (Thioceras lon<iiceps, Marsh, No. 1256, female.) 



m. 



Greatest length of ramus (approximate), . . _ 0.57 



Extent of symphysis, i . . . . . _ 0. 1 8.5 



Height of coronoid process from bottom of ramus, 0.26 



Depth of ramus at last molar, . 0.084 



Depth of ramus at tusk process, 0.10 



Extent of diastema, 0.145 



Extent , of molar .scries, ... .. . 0,175 



Transverse dianu'ter of condyle, .. .. 0.070 



Vertical diameter of condyle, 0.045 



