1900.] SHUFELDT—OSTEOLOGY OF THE STRIGES. 707 
The external and lower condyle is divided in two by a vertical 
excavation, deepest above. Of the two facets thus formed, the 
inner articulates with the tibia, the outer with the head of the 
fibula. The external surface of this condyle is flat and continuous 
with the shaft. The inner condyle, broad posteriorly, has a slight 
depression in the surface that bounds it on the tibial side, and as a 
rule the usual sites for ligamentous attachments about this extremity 
are at best but feebly represented. The patella, encased in the 
tendon of the quadriceps femoris, is situated about three millimetres 
above the rotular crest of the tibia, anteriorly, having the form of 
an oblate hemispheroid with its base directed upward, the long 
diameter of which measures 3.5 millimetres. The tibia is the 
longest bone in this bird’s skeleton, and at the same time, taking 
this length into consideration, the least curved or bent along the 
shaft; it has, however, a slight and appreciable gradual curva- 
tive forward that is most apparent about the junction of middle or 
upper thirds. Its average length, measured on the inside, is 6.7 
centimetres ; its extremities being expanded for articulation, above 
with the femur, below with the tarso-metatarsus. These expansions 
are of about equal dimensions, though differing vastly in form; in 
this respect being unlike some of the diurnal Raffores, in which 
the distal condyles constitute the smaller end of the bone. 
Among the most important points presented for examination 
about the head is the articular surface that crowns it above for the 
condyles of the femur. This is subquadrate in form, uneven, 
highest at the anterior and inner angle, sloping gradually to the 
opposite one, bounded almost entirely around by a raised margin, 
that is most feebly developed posteriorly and at a point anterior to 
the head of the fibula, where it is absent. In front, this border may 
be nominated the’ rotular or epicnemial ridge, though it is no more 
prominent there than at any other point ; but jn many birds it is so 
produced as to form a process of some size, to which these terms 
are applied. Externally and posteriorly the margin is roughened 
for the attachment of ligaments that bind the head of the diminu- 
tive fibula to this bone. In the middle of this articular surface is 
to be seen a tuberosity, on either side of which are the depressions 
for the femoral condyles. Produced downward, anteriorly, from 
the rotular ridge are the cnemial ridges; these have their crests 
bent slightly forward, and they merge into the shaft below, abreast 
the superior point of the fibular ridge. Of the two, the outer or 
