214 Prot. O. C. Marsh on Hesperornis regalis and 



although an approach to the same structure is seen in the 

 genus Podiceps. On the outer inferior margin thej are all 

 deeply excavated. The first, second, and third have, at their 

 distal ends, a single oblique articular face on the inner half 

 of the extremity ; and the outer portion is produced into an 

 elongated obtuse process, which fits into a corresponding 

 cavity in the adjoining phalanx. This peculiar articulation 

 prevents flexion except in one direction, and greatly increases 

 the strength of the joints. The terminal phalanx of this toe 

 was much compressed. The third or middle toe was greatly 

 inferior to the fourth in size, and had slender compressed 

 phalanges, which correspond essentially in their main features 

 with those of modern Divers. The phalanges of the first and 

 second toes of the present specimen are wanting. 



Portions of the pelvis, found with the posterior limbs in 

 three of the specimens, indicate that the ilia were separated 

 from each other, and not very firmly ossified to the sacral 

 vertebrae. The acetabulum was covered with a thick cushion 

 of cartilage, as in Apteryx ; and at its upper margin the 

 anterior and posterior extensions of the ilia, if both existed, 

 were disconnected, or unossified at their union. 



The cervical and caudal vertebrjB preserved present no fea- 

 tures deserving of special mention in this preliminary notice. 

 The latter are numerous, but apparently not much in excess 

 of those in some modern birds. Unfortunately, no portions 

 of the skull were recovered. The femur and tibia have very 

 thick compact walls, but appear to have been more or less 

 pneumatic. The tarso-metatarsals and the phalanges were 

 nearly or quite solid. 



millims. 



Length of right femur 98 



Transverse diameter of proximal end 53 



Diameter of articular head 18-5 



• Transverse diameter of shaft at middle 22 



Antero-posterior diameter 19-2 



Transverse diameter of distal end 53-5 



Length of right tibia 316 



Transverse diameter of proximal articulation 38 



Length of cnemial process 22 



Transverse diameter of shaft at middle 29 



Transverse diameter of distal end 32 



Antero-posterior extent of outer condyle 32 



Autero-posterior extent of inner condyle 22 



Length of right tarso-metatarsal 137 



Length to distal end of third metatarsal 130 



Length to distal end of second metatarsal 116 



Transverse diameter of proximal articulation 36 



