TI4 ON THE STAGONOLEPIS ROBERTSONI AND THE 
three pairs of right-foot prints (of the fore and hind foot on each side) 
and two pairs of left-foot prints. 
(Fore Foot..—The most distinct impression of the anterior foot 
(fig. 4) is the middle one of the three on the right side. Its greatest 
breadth is 23 inches, its greatest length 32 inches. The plantar 
surface of the foot measures 14 inch in its greatest anterior-posterior 
diameter. The impressions of five digits are visible ; and the proxi- 
mal joints of the third digit, taken together, equal rather more than 
an inch in length, while the impression of its terminal joint is 14 inch 
in length. 
This plantar impression is on the whole transversely oval, its 
anterior boundary presenting a tolerably even convexity forwards, 
while the posterior boundary, equally, or more, convex backwards, 
presents an emargination opposite the base of the middle digit. A 
line drawn from the emargination to the base of the fourth digit 
would divide the plantar impression into a shallow outer portion 
and a more deeply concave inner portion. A line drawn from the 
emargination to the interspace between the first and second digits, 
again, would divide the concave inner surface into a deeper external 
portion and an internal portion, the latter gradually shallowing 
towards the inner side, and passing into the impression of the inner 
digit, which diverges so much from the direction of the others, and 
seems to have been comparatively so thick and short, that it might 
well be termed a thumb. The proximal portion of this thumb seems 
at first to terminate in a strong curved impression convex outwards 
and forwards, and deepest internally, which has somewhat the shape 
of a comma set transversely ( « ). 
The distance from the emargination to the end of this impression 
is 1% inch; beyond it is an interval of 3ths of an inch; and then 
follows a shallow longitudinal mark, ? inch long and nearly } inch 
broad, which takes a direction nearly parallel with that of the ungual 
phalanges of the other digits, and terminates opposite the base of the 
ungual phalanx of the second digit. 
The last-mentioned features are only to be made out by examining 
the tracks very carefully by artificial, or by very oblique natural, 
light! Whether, as I originally supposed, the deep comma-shaped 
impression is the mark of a nail covering the second phalanx, or 
whether it has been produced by the first phalanx,—the longitudinal 
mark being the true impression of the second phalanx,—is a point 
1 T had not done this when my account of Stagonolepis was given to the Society, and 
hence, in the abstract of my communication, the comma-shaped impression is described as 
the mark of a ‘‘ thick, short, and much-curved nail.” 
