y8 NEW YORK STATE MUSEUM 



of the shaft of the tibia, we find a long, well developed, fibular 

 ridge, for the usual articulation of that bone. Farther dov/n the 

 shaft its continuity is subcylindrical on section, at least as far as 

 where it begins to become anteroposteriorly flattened above the 

 condyles. 



The usual oblique bony bridge for the retension of tendons is 

 seen on the anterior aspect just above the condyles, and above it 

 again the two tubercles, one on either sid§, for the attachment of 

 the ligament that performs a similiar function. Of these latter the 

 inner is the higher on the shaft. The tibial condyles are nearly of 

 a size, the outer one being produced the farther up the shaft pos- 

 teriorly. In this situation the articular surface merges across the 

 intercondyloid space. On the outer aspect of the inner condyle a 

 hemispherical tubercle forms a striking object. Circus has but a 

 single patella. This bone is of a cordate form with the rounded 

 apex below, and a transversely truncate surface above. Posteriorly 

 it is more convex than it is anteriorly, and it has a transverse 

 diameter of five millimeters at its greatest width. 



The fibula [fig. 30, 32] is laterally compressed above, the hinder 

 part of its head extending backward over the shaft. It does not 

 rise above the articular plane of the tibia, and only touches it above 

 near its anterior and inner angle [fig. 30]. At 1. 3 centimeters down 

 its shaft it comes in contact with the fibular ridge of the til)ia, op- 

 posite which it develops on the outer side of its shaft the usual 

 tuberosity for the insertion of the tendon of the biceps. Its con- 

 tact with the fibular ridge extends for two centimeters along the 

 tibial shaft. Below this the fibula does not again come in contact 

 with the latter until it passes its middle point from whence its 

 needlelike dimensions may be traced in close contact with the main 

 bone of the leg to the juncture of its middle and lower thirds. 



The Marsh harrier presents us with a very interesting form of a 

 tarsomctatarsus [fig. 31, 33, 34]. Viewing its proximal extremity 

 directly from above [fig. 33] we note that there are two distinct pro- 

 cesses representing the " hypotarsus." The inner of these is the 

 longer, and both have slightly dilated extremities. They are at 

 right angles to the shaft, and separated from each other by an in- 

 terval of four millimeters, the base of the intervening valley being 

 roundly concave from side to side. The articular surface at the 

 extremity of the tarsomctatarsus presents two well marked de- 

 pressions for the condyles of the tibia. They are separated in the 

 middle line by a slight convexity. Upon direct front view this bone 



