Heels overlapping when hind limbs adpressed; tibiotarsal articulation reaches to middle of eye; no tarsal fold; inner metatarsal tubercle large, flat, and elliptical; outer metatarsal tubercle small, elliptical, slightly more distal than inner; subarticular tubercles round; length of digits from shortest to longest 1-2-5-3-4; third and fifth toes webbed to base of disc; fourth toe webbed to base of penultimate phalanx; discs smaller on toes than on fingers.
"A Review of the Middle American Tree Frogs of the Genus Ptychohyla"
William E. Duellman
"The heel of the horse is the part commonly known as the hock; the hinder cannon bone answers to the middle metatarsal bone of the human foot, the pastern, coronary, and coffin bones, to the middle-toe bones; the hind hoof to the nail, as in the fore foot.
"Thomas Henry Huxley; A Sketch Of His Life And Work"
P. Chalmers Mitchell
The bones, which, in the horse are represented by two long splints, imperfect below, are as long as the middle metacarpal and metatarsal bones; and, attached to the extremity of each, is a digit with three joints of the same general character as those of the middle digit, only very much smaller.
"Thomas Henry Huxley; A Sketch Of His Life And Work"
P. Chalmers Mitchell