PROFESSOR OWEN ON THE AYE-AYE. 53 



cave backwards. They diverge to the tuberosities (<) for an extent about equal to that of 

 the ischio-pubic symphysis, the tuberosities being shghtly everted : a small projection 

 (fig. 19, 63) behind the lower part of the acetabulum divides the great from the small 

 ischiadic notches, both of which are very shallow. The obturator foramina (o) are 

 oval, 9 lines by 6 lines in the two diameters. The pubic bones (ib. e*) pass from 

 the acetabula (fig. 19, a) at almost a right angle with the ilio-ischial axis; they con- 

 verge to the symphysis (64, s) at an angle of 80°. There is a slightly marked ilio- 

 pectineal prominence. 



The femur (PI. XIX. es) has a straight shaft, with the upper end a little inclined for- 

 ward, and the lower joint projecting as much backward : it is one-third longer than the 

 humerus. The head (Pi. XXI. fig. 21, a) is an oblong or subeliiptic convexity, with 

 the longer axis from behind forward and downward, having the pit for the round liga- 

 ment near its lower border. The neck is short : the great trochanter (t) rises to the 

 height of the head ; it diminishes in breadth as it descends, and at the outer and lower 

 part is developed into a small tubercle [u). Opposite to this the lesser trochanter (s) 

 projects from the inner side to a greater degree. The shaft of the femur is, transversely, 

 less convex behind than before ; it preserves its shape and thickness to the beginning 

 of the condyloid expansion. The orifice for the medullary artery is at the back part, 

 one-fourth of the length from the head : the canal ascends. The inner condyle is rather 

 the largest. The outer border of the rotular groove projects most. There is a sesamoid 

 bone (PI. XIX. es) in each origin of the gastrocnemius. 



The tibia {ib. ee) is about two lines shorter than the femur, and soon contracts below the 

 head to a compressed shaft, giving a long and narrow subeliiptic section ; at the upper 

 half it is very slightly bent, with the convexity forwards. A roughish surface is con- 

 tinued from the tuberosity nearly one-third of the way down the fore and outer part of 

 the shaft. The orifice of the medullary canal is one-fourth of the way down, just within 

 the posterior border: the canal slopes downward. The malleolar part of the distal 

 expansion is long : two slight vertical ridges at the back part of the expansion bound 

 a wide and shallow groove for the flexor tendons. The tibia is one-fifth longer than the 

 ulna. The fibula (ib. e;) touches the tibia only by the two extremities articulating with that 

 bone, leaving an interosseous space co-extensive with their shafts. The outer malleolus 

 is shorter and thicker than the inner one. There is a sesamoid in the external lateral 

 ligament of the knee-joint, at its insertion into the liead of the fibula. 



The tarsal bones (Pi. XIX. es, PI, XXI. fig. 22) are seven in number. The naviculare 

 (s) has its shallow concavity for the astragalus (a) supplemented by the strong 

 ligament arising from its posterior and inferior margin, and inserted into the fore part 

 of the inner malleolus ; anteriorly it articulates with the three cuneiform bones, and 

 externally at its fore part with the os cuboides ; its depth exceeds its length. The 

 astragalus (a) has a grooved posterior border ; the upper articular surface is broader 

 before than behind. The part thence extending to the anterior ball, with the rest of 



