FEET OF HESPERORNIS. 99 



Vertical diameter of median distal articulation, mm 14.4"- r 



Transverse diameter of inner distal articulation, 9.0 9.0 



Vertical diameter of inner distal articulation, 11.5 11.5 



Measurements of Tarso-metatarsus. (Hesperornis gracilis, No. 1478.) 



Left. Eight. 



Length to end of outer articulation, 138. mm mm 



Length to end of median articulation, 133.0 



Length to end of inner articulation, 117.0 



Antero-posterior diameter of proximal end, 19.0 



Transverse diameter of proximal end, 31.0 



Antero-posterior diameter of inner metatarsal, at the middle, 16.0 



Antero-posterior diameter of outer metatarsal, at the middle, . . 18.0 



Transverse diameter of shaft, at the middle, 12.0 12.0 



Transverse diameter of outer distal articulation, 14.0 14.0 



Vertical diameters of outer distal articulation, 12-10-1 7.0 12-10-16.5 



Transverse diameter of median distal articulation, 7.5 7.5 



Vertical diameter of median distal articulation, 14.0 14.0 



Transverse diameter of inner distal articulation, 7.0 7.0 



Vertical diameters of inner distal articulation, 10-12.0 10.5-13.0 



Measurements of First, or Hallux, Metatarsal. (Hesperornis regalis, No. 1476.) 



Length of first metatarsal element, 20.0 mm 



Greatest diameter of distal end, 8.0 



Least diameter of distal end, 3.0 



Greatest thickness of shaft, 3.0 



The Feet of Hespeeoenis. (Plate XX.) 



The feet of Hesperornis resembled more closely those of the genus 

 Podiceps than of any. other known birds. The number of digits is the 

 same, the number of phalanges in each digit identical, but the proportions 

 of the latter are different, and quite peculiar. In Podiceps, and the other 

 Grebes, the outer toe is indeed the longest, but the middle one almost 

 equals it in length and size, while the second is but slightly smaller. In 

 Hesperornis, however, the fourth, or outer, toe is the dominant one, being 

 three or four times as powerful as the adjoining middle one, or indeed, as 

 the other three combined. Again, the phalanges in Podiceps are very 

 elongate and slender, and the terminal ones spatulate, while, in Hesperornis, 

 the phalanges are short and thick, with the terminal ones more or less 

 pointed. The phalanges in Hesperornis are, in fact, shorter than in most 



