Hitchcock.] 
124 
fDec. 19, 
the stone and one of the impressions was made by the animal when 
walking across his first line of march. Handsome ripple marks also 
cover the slab. Following the example of the Ichnology, the more 
important characteristics of the animals as shown by their impres- 
sions may be specified as follows : — 
Hind foot. Four-toed ; three of the toes bird-like, attached to the 
tarso-metatarsal bone, and the fourth placed higher up like a spur. 
Toes pachydactylous, joints not distinct on the type specimen, 
though they must conform to the usual number of three in the in- 
ner, four in the middle and five in the outer toe, in all cases includ- 
ing the ungual phalanx. The tarso-metatarsal bone was frequently 
brought to the ground, making an impression amounting to about 
one-half the length of the whole foot. Average divarication of the 
long lateral toes, 90° ; between the outer and middle and between 
the inner and middle, 45°. The fourth toe is usually parallel with 
the inner toe and divergent outwardly when not parallel. Distance 
of this mark from the foot, .8 inch. Length of the inner toe in ad- 
vance of the heel, 2.35 inches ; of the middle toe, 3.2 inches ; of the 
outer toe, 2.85 inches ; of the foot, 4.5 inches ; of the fourth toe, 
1 inch ; of the step, 13 to 13.5 inches ; of the stride, 26.5 inches, 
of the heel, 2.12 inches as exposed. Toes, .6 inch wide. Track- 
way from 7.25 to 8.25 inches wide. The claws of the middle toe 
turn slightly inward. 
Front foot. Pachydactylous, pentedactylous, unguiculate, di- 
gitigrade. Phalangeal impressions indistinct. Width of foot, 1.85 
inch. Length from anterior to posterior part, so far as exposed, 
1.35 inch. Length of toes in order, beginning with the inner, .615, 
.750, .850, .750, .700 inch. 
The locality is Lily Pond, Gill. 
Upon slab No. at Amherst are several tracks of this species. 
The specific name is bestowed to commemorate the interest taken 
by the Mt. Holyoke institution in the subject of Ichnology and in 
view of the fact that the type specimen is in their possession. 
Apatichnus crassus. The same genus appears upon the slab 
at New Brunswick from Whitehall. The inspection of drawings 
proves it to be a larger species, the length of the foot being 5.6 
inches. The impression of the fourth toe is about one-half inch 
long and is removed from the foot mark itself nearly 1.5 inches. 
Anomcepus isodactylus. It will not be necessary to describe the 
characters which this species has in common with the others of the 
