Vol. 6] Miller: Condor-like Vultures of Rancho La Brea. 17 



Further marking of the face of the bone is limited to a single 

 longitudinal intermuscular line which begins on the outer side of the 

 outer tubercle of the tibialis anticus, passes rather quickly to the median 

 line, and leaves the median line at about the middle of the shaft to pass 

 over to and occupy the inner border, where it disappears at a point 

 about three-fourths the way down the tarsus. 



Posterior aspect. — Viewed from this direction No. 12599 most nearly 

 approaches S. clarM in appearance. The general profile at the head end 

 is at right angles to the axis instead of being raised at the inner 

 border. The intercotylar tuberosity is almost invisible. Externally a 

 sharp break in the profile is produced by a high and pointed tubercle 

 situated at the posteroexternal point of the outer articular facet. The 

 hypotarsus is slightly lower than in C. gracilis and, unlike the forms pre- 

 viously described, the lower border of the hypotarsus does not merge 

 into the longitudinal ridge at the back of the shaft. Instead of being 

 roughly triangular the hypotarsus is more nearly a quadrangle. Its distal 

 margin is a well-defined transverse ridge elevated distinctly above the 

 median longitudinal ridge of the shaft. The limiting ridges and inter- 

 muscular line are much the same as in C. gracilis. 



The plantar opening of the distal foramen is very large and is placed 

 very low, so that in the type specimen its distal margin breaks down 

 into the external intertrochlear space. This character is constant in 

 the series of four specimens. In a corresponding position above the 

 inner intertrochlear space there appears a rounded depression, found in all 

 specimens of the species and marking the entry into the bone of one 

 or more foramina which are probably nutrient in nature. 



Proximal articular surface. — From this point of view several inter- 

 esting features are noticeable. The two articular facets are relatively 

 short in their anteroposterior axes, yet the head seems deep in this 

 direction because of the unusually wide, smooth depression between 

 the articular portion and the hypotarsus. The tubercle on the anterior 

 border of the outer facet throws this portion of the anterior profile of 

 the head out beyond the convexity of the intercotylar tuberosity and 

 renders the profile between these two points abruptly concave. The 

 anterointernal margin is again produced but more gradually until it 

 reaches a point slightly beyond the intercotylar tuberosity. 



The external border of the head is marked by three salient points, 

 the first near its anterior limit, the second at the posterolateral limit 

 of the external facet, and the third at the posterolateral extremity of 

 the hypotarsus. 



The posterior margin of the hypotarsus does not differ essentially 

 from the same profile in the other condors. The inner hypotarsal ridge 

 is produced to a slightly less degree than is shown in C. gracilis. The 

 inner profile of the bone from this point of view is very much like 

 that of gracilis. The most prominent point is very near the postero- 

 lateral margin of the inner facet. From this point the outline sweeps 

 backward and centrally in an open curve to the internal margin of the 

 hypotarsus. The intercotylar tuberosity from this direction is scarcely 

 visible, its margins are so ill defined. The depression which commonly 



