25 
Osteological Studies of the Subfamily Ardeince. 
at its proximal end which bears a circular facet on the lateral 
aspect, to articulate in life with the surface described above on the 
tarso-metatarsus. Thus it is that this bone is so mobile, and can 
be thrown backwards to a considerable distance. Below, it bears 
a trochlea for the rear phalanx of hallux, which reaches higher on 
its shaft on the digital side of the bone, being faintly grooved on 
the other. The entire length of this segment is 1.7 centimetres. 
At the proximal end of the first phalanx of hallux, the troch¬ 
lear surface is far more extensive than its opposed surface on the 
first metatarsal, being fully half as broad again. The shaft is 
rather slender, gently curved throughout, convex upwards, and 
subcylindrical on section. Its distal trochlear surface is princi¬ 
pally on the under end of the bone, rather narrower transversely, 
and shows a shallow median longitudinal groove. The oval sides 
of this extremity are marked by pits for ligamentous attachment. 
It measures in extreme length 4.6 centimetres, being the longest 
phalanx of the pes. 
Its osseous claw is rather more than moderately curved, shows 
the usual trochlear surface and the tubercle for tendinal insertion. 
The distance from this latter point to the apex measures 1.6 cen¬ 
timetres. Both the convex surface above and the concave surface 
beneath is uniformly rounded off, while the bone is laterally com¬ 
pressed. A groove distinctly marks it on either side, but is not 
quite carried to the apex. 
Second digit has three phalanges including the ungual one ; 
the proximal phalanx has all the characters as given for first joint 
of hallux, it, however, is distinguished by a prominent tubercle 
to the inner side of the articular surface for the trochlea of tarso- 
metatarsus. The bone is rather stouter and somewhat shorter. 
The second joint is a still shorter and a slighter bone ; its proxi¬ 
mal trochlea is concave from above, downwards, very slightly 
convex in the opposite direction. The shafts of these bones are 
not curved to such a degree as we found the shape of first joint of 
hallux to be, and the proximal ones are always the straightest. 
Agreeing even in minor details, the ungual phalanx of this second 
digit is smaller than the one found in the first toe, but shows 
about the same amount of curvature. These three joints measure 
from proximal to distal one, respectively 4.4, 3.1 and 1.1 centi¬ 
metres ; the ungual joint being measured as I measured the bony 
claw of the first digit. 
