1900.] SHUFELDT—OSTEOLOGY OF TITE WOODPECKERS. Gl? 
and separated in front, below and behind by a deep intercondy- 
lar notch. A pit is seen in the middle of this, below, for a con- 
‘spicuous process standing up on the summit of the tarso-meta- 
tarsus. ; 
Antero-posteriorly the articular facet on the summit of the fibula 
is concave. Just now I invited attention to the erect process 
standing between the concave articular facets upon the summit of 
the tarso-metatarsus in the Pileated and other Woodpeckers. This 
bone of the leg shows further that its hypotarsus is bulky, being 
both deeply grooved and perforated for the passage of the ten- 
dons. Its shaft is straight, rather small comparatively, and only 
slightly grooved down its length in front and not so at all be- 
hind. Distally the trochleze are large and prominent, and among 
our Pici we find two patterns of these, one being as they occur 
in Ceophéeus, now in hand, and the other as they occur in the three- 
toed forms, such as Prcotdes. They differ, however, but very little, 
as the difference in /Pzcotdes is a suppression of the first toe and 
the small, free first metatarsal. Evidently this does not affect the 
form of the trochlez of the tarso-metatarsus to any extent. 
Turning to the Pileated Woodpecker again, we find a very 
interesting state of affairs, for the trochlea for the inside anterior 
toe is single and much compressed lateralwise ; the one for the 
outer anterior toe is double, or, in other words, has two condyles 
with the median valley running round between them. Then comes 
the single trochlea again for the fourth toe or the outside hinder 
one. It is turned to the rear and articulates with the basal joint 
of the reversed toe. Posterior to this is a very large, irregular, 
freely-projecting trochlea, which articulates with a sesamoid at the 
back of the foot. This sesamoid is moulded on to the inner side of 
the base of the basal joint of the reversed toe and to some slight ex- 
tent on to the base of the basal joint of the hind toe proper. Indeed 
it stands between them, and the trochlea intended for it is fully 
three times as large as the one for the fourth or reversed toe. 
The accessory metatarsal is comparatively very small and freely 
suspended as usual. Considerable feebleness seems to character- 
ize the true hind toe of the Woodpecker under consideration. 
Its basal joint is much compressed from side to side, and indeed 
this is the case with all these joints of the podal digits, it being 
especially noticeable in the first and second toes. The osseous 
claw to the first toe is also comparatively small, but the outer 
