406 0. CG. Marsh—Odontornithes, or Birds with Teeth. 
The tibia is straight and elongated. Its proximal end has a 
moderately developed cnemial process, with an obtuse apex. 
The epi-enemial ridge is prominent, and continued distally 
about one-half the length of the shaft. The distal end of the 
tibia has on its anterior face no ossified supratendinal bridge, 
differing in this respect from nearly all known aquatic birds. 
The fibula is well developed, and resembles that of the Divers. 
The patella is large, as in Podiceps, and in position extends far 
above the elevated rotular process of the tibia. 
e tarso-metatarsal bone is much compressed transversely, 
and resembles in its main features that of Colymbus ts 
the third or fourth, and its trochlear end resembles in shape 
and size that of the fo The existence of a hallux 3s 
indicated by an elongated oval indentation on the inner margin 
above the articular face of the second metatarsal. The free 
extremities of the metatarsals have the same oblique arrange 
ment as in the Colymbide, to facilitate the forward stroke of 
On the outer, inferior margin, they are all deeply excavated. 
The first, second, and third have, at their distal ends, a cing 
oblique, articular face on the inner half of the extremity, 0 
which fits into a corresponding cavity in the adjoining phalanx. 
This peculiar articulation prevents flexion except in one 
irecti reatly increases the strength of the joints. The 
of this toe was much comp ae mee 
_ or middle, toe was greatly inferior to the fourth in size, and ba 
