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



7 



without reserve to the existing species Gymnogyps calif or niauus. 

 Careful scrutiny fails to show any important difference between 

 any member of the series and the single available specimen of 

 the Recent form. This Recent specimen consists of the tibiae, 

 tarsi and wing bones of a male bird presented by Mr. Otto Zahn 

 of Los Angeles, California. The bird was taken in Santa Barbara 

 County, California, and was said to be a large male. The only 

 dimensions obtainable from the specimen as it came to the 

 author's hands were the wing and tarsal lengths. These were 

 29 inches and 4.50 inches respectively. Coues records the wing 

 measurement as 24 to 36 inches and the tarsus 4.50 to 5.00 

 inches. This bird thus appears to have been about the average in 

 size and, as the females are not larger than the males, probably 

 represents the species fairly well. 



All the fossil tarsi of this species are larger than the Recent 

 specimen — with total lengths ranging from 120 to 131 mm. The 

 Recent specimen measures 116.8 mm. in length. A typical mem- 

 ber of this series of fourteen bones is No. 12161, a description 

 of which is here inserted : 



Typical specimen. — No. 12] 61, Univ. Calif. Col. Vert. Palae. Tarso- 

 metatarsus taken from Bancho La Brea beds at a depth of 6 feet 4 

 inches. The specimen is a typical cathartine tarsus measuring 126 mm. 

 in total length, with a maximum transverse shaft diameter of 13.9 m. m. 

 Viewed from in front the head shows a prominent rounded intercotylar 

 tuberosity rising between the facets of the tibial condyles. The sides 

 of this tubercle slope abruptly down to the border of the external facet 

 and more gradually to the internal facet. Below this tuberosity the 

 shaft is deeply excavated by the proximal part of the anterior furrow 

 which here reaches its widest and deepest development. Two foramina 

 here pierce the bone from anterior to posterior passing through to open, one 

 internal and the other external to the hypotarsus. In the median line the 

 furrow is slightly interrupted by an irregular rugosity for the attachment 

 of the tibialis anticus. Except for this slight interruption the anterior 

 furrow becomes very gradually narrower and shallower as it passes 

 down the shaft. At about three-fourths the way down, this furrow, by 

 a very slight deviation toward the exterior, passes almost insensibly into 

 a furrow leading to a foramen piercing the bone just proximal to the 

 outer intertrochlear space, the distal foramen, through which the adductor 

 tendon to the outer toe and the anterior tibial artery pass. At no point 

 in its length does the anterior face of the shaft cease to be at least 

 slightly concave transversely. 



At its distal end, where the bone widens out to the distal trochleae 

 the inner profile is concave on a shorter radius than is the outer. This 



