878 THE WHITE EIVER FAUNA. 



men of this age furnished the basis of the Palceolagus agapetillus. Its meas- 

 urements are : 



Measurements. 



i£. 



Length of molar series 0100 



Length of penultimate molar • 0020 



Depth at penultimate molar 0070 



Depth at first molar 0050 



Transverse thickness at first molar 0037 



There is the merest trace of a posterior lobe at this time, and that speedily 

 disappears. The anterior lobe is subconical, and is entirely surrounded with 

 enamel. By attrition, the two lobes are speedily joined by an isthmus, 

 and for a time the tooth presents an 8-shaped section, which was supposed 

 to be characteristic of the genus. Further protrusion brings to the surface 

 the bottom of the groove of the inner side of the shaft, so that its section 

 remains in adult age something like a B. 



The measurements of a medium-sized adult are — 



Measurements. 



it. 



Length from interorbital region to end of nasal bones (Spec. No. 1) 0.0250 



Length of median suture nasal bones OICO 



Width at interorbital region 0080 



Width between anterior borders of orbits 0180 



Width at front of rugose patches 0110 



Width of nasal bones at middle 0080 



Width of nasal bones at extremity 0060 



Width of anterior incisors together 0050 



Width of posterior incisors together 0035 



Width of incisive foramen at M. 1 0040 



Width of palate at M.l 0075 



Width of palate at M. 6 0080 



Length of superior diastema •- 0120 



Length of superior molar series 0110 



Width of first molar 0020 



Width of third molar 0033 



Length of inferior molar series (Spec. No. 21 .012 



Length from M. 1 to end of incisor 012 



Length of diastema OOS 



Length of crown i f M. 1 0029 



Elevation of crown of M. 1 above alveolus 0035 



Depth .at M. 1 00/0 



Depth atM. 5 0085 



Inferior diameter of ramus below M.l 0040 



The shaft of the humerus is subround at the middle. The external crest 

 from the epicondyle extends by a long curve to the posterior side of the shaft 

 where it ceases. The external extremity of the condyles is occupied for the 



