179 



lateral surfaces of the expanded part are slightly concave, and 

 the upper articular surface is much elongated from before back- 

 wards and deeply grooved in its front half for the patella. In 

 the posterior part there is an articular surface separated into two 

 facets by a notch. The inner, and larger, is concave ; the outer, 

 and smaller, is convex, and is placed upon an outwardly projecting 

 process. Both of these are for the femur. On the outer and under 

 surface of the projecting process, just mentioned, and continuous 

 with that for the femur, is a small flat facet for the fibula. 



The inferior extremity articulates with the fibula, and is pro- 

 longed into an internal malleolus. 



The shaft of the fibula (fig. 7) is slender, lying so far behind 

 the tibia, as to stand almost clear of its posterior border. 

 Its upper extremity is expanded into two flattened, and 

 almost hook-like processes, which project fore and aft, and, on the 

 inner surface of the bone, at the junction of the shaft with these 

 expansions, is an articular facet looking upwards and inwards, 

 which is partly for the tibia and partly for the femur. Of 

 the expanded processes, the anterior comes to a point, but the pos- 

 terior terminates behind in a broad slightly inflected border. Mid- 

 way between the two and immediately above the facet for the 

 superior tibio-fibular articulation is a large foramen (o). 



Below, the shaft expands into an inferior extremity, which is 

 prolonged into an external malleolus, and the tibia and fibula 

 together furnish an articulation, concave from side to side, for the 

 astragalus. 



The patella (fig. 7 p) is relatively very large and irregular, 

 and generally flattened from side to side for the anterior two- 

 thirds ; in the remainder it is somewhat laterally expanded. On 

 its posterior face it has a large flat facet, which plays upon the 

 inferior femoral articulation, as described under that bone. The 

 inferior border is brought to a sharp ridge, which fits into the 

 groove, described as existing, upon the front part of the head of 

 the tibia. The outer surface is somewhat concave from before 

 backwards ; the inner rough. 



THE PES. 



(PI. VIIL, figs. 8, 8a, 8b.) 



The pes departs so much less from the normal type than the 

 manus, that I need only confine myself to a description of the 

 parts which present peculiarities. 



The calcaneum extends considerably backwards as a long bony 

 spur (fig. 8 ca). The scaplioid (sc), deeply concave towards the heel, 

 articulates in front with a consideraljle internal and small middle 

 cuneiform {ic and mc). Tliese two carry respectively the hallux 

 and second digit. There is a large irregular cuboid {cu), which 



