87 
probably the union of the metatarsal pads. There is no pad for the proximal 
portion of phalanx one of digit II and this toe is separated from the rest 
of the foot. The fact that the weight of the animal was thrown strongly 
•to the outside and that it did not sink deeply into the mud may help to 
explain this separation. The central toe is longest and most deeply 
impressed, indicating that it carried most of the weight. 
The toe pads are not in all cases distinctly shown, but by careful 
examination the following formula can be made out: digit II, three pads; 
digit III, four pads; and digit IV, four pads. The toes are moderately 
long and slender and the distal extremities of the impressions indicate 
moderately broad, flat claws rather than sharp, decurved ones. The shallow- 
ness of the impression and the position of the tracks, e.g, one straight 
ahead of the other, indicate a lightly built, long-legged animal walking 
more or less upright. 
Oyster shells were observed at an horizon about 20 feet below the 
tracks and it is probable that the mud-flat on which the animal walked 
was not much above sea-level. The above-mentioned oyster shells are 
at the same horizon as the oyster bed which is quite general farther down 
stream and is more than 2 feet thick at some localities. 
An examination of the known fauna of the Edmonton formation 
reveals only one animal which would make tracks similar to those here 
preserved, e.g. Ornithomimus. A study of the hind feet of Ornithomimus 
leaves very little doubt that the tracks were made by an animal of that 
genus or at least a member of the family Ornithomimidae. The name 
Ornithomimipus angustus is proposed for these footprints and the best 
one (Plate XVIII, Cat. No. 8513) is considered as the type. The specific 
name refers to the slenderness of the tracks as compared with other 
Cretaceous dinosaur footprints. 
Mm. 
Greatest length of track . 280 
Length from distal extremity to end of digit II 190 
Length from distal extremity to end of digit IV 170 
Greatest breadth from tip to tip of side toes 200 
Greatest breadth of central toe pad 50 
Length of stride 940 
