92 ODONTORXITHES. 



the two condyles, when seen from the front, is sub-equal, and the groove 

 between them does not correspond with the axis of the bone, but is some- 

 what inclined inward. There is no osseous bridge in front, over the canal 

 through which passes the tendon of the tibialis anticus muscle. The 

 absence of this osseous bridge is noteworthy also in Podiceps, as it is 

 apparently present in all other known aquatic birds. The groove between 

 the posterior projections of the two condyles is broad, and flat, but narrows 

 rapidly above. 



In the tables below will be found detailed measurements of the tibia 

 of Hesperornis regalis, in the type, and in one other specimen : 



Measurements of Tibia. (No. 1200.) 



Left. Right. 



Length of tibia, 320.0 mm 320.0 m 



Elevation of cnemial process, 22.0 22.0 



Greatest diameter of proximal articular surface, . . -. 35.0 38.0 



Transverse diameter of inner proximal articular surface, 18.0 20.0 



Antero-posterior diameter of inner proximal articular surface, 26.0 



Transverse diameter of outer proximal articular surface,. 18.0 19.0 



Antei-o-posterior diameter of outer proximal articular surface, 14.0 15.0 



Transverse diameter of shaft below fibular ridge, 23.0 



Antero-posterior diameter of shaft below fibular ridge, 16.0 



Transverse diameter of distal articular surface, 26.0 32.0 



Antero-posterior diameter of external condyle, 32.0 



Antero-posterior diameter of internal condyle, 19.0 19.0 



Depth of groove between condyles, 9.0 8.0 



Measurements. (No. 1476.) 



Left. Eight. 



Length of tibia, 335. mm 325. m 



Elevation of cnemial process, 21.0 23.0 



Greatest diameter of proximal articulation, 33.0 36.0 



Transverse diameter of inner proximal articulation, 17.0 18.5 



Antero-posterior diameter of inner proximal articulation, 23.0 22.0 



Transverse diameter of outer proximal articulation, 15.5 15.5 



Antero-posterior diameter of outer proximal articulation, 12.5 



Transverse diameter of shaft below fibular ridge, 21.5 22.0 



Antero-posterior diameter of shaft below fibular ridge, 16.5 16.5 



Transverse diameter of distal articulation, 26.0 32.5 



Antero-posterior diameter of external condyle, 32.5 30.5 



Antero-posterior diameter of internal condyle, 20.0 



