14 University of California Publications. [Geology 

 Table of Measurements. 



Tarso-metarsus. 



Total length 127.1 mm. 



Greatest transverse diameter of head 27.3 



Greatest sagittal diameter of head 22.8 



Greatest transverse diameter through troehleae 29.6 



Greatest transverse diameter of middle troehleae 12.1 



Greatest sagittal diameter of middle trochlea 16.9 



Least transverse diameter of shaft 12.4 



Sagittal diameter at middle of shaft 10.0 



Width of partition between proximal foramina 4.0 



Transverse diameter of pit into which proximal foramina 



open 7.6 



Longitudinal diameter of same 11.9 



CATHAKTOENIS GRACILIS, n. gen. & sp. 



Type specimen No. 12598 and cotype No. 12600, Univ. Calif. 

 Col. Vert. Palae. Tarso-metatarsus. 



Extremely slender front of shaft strongly grooved throughout 

 its length. Inner ridge of hypotarsus much the more prominent. 



Shaft of tarsus relatively narrow and thick, the excavation 

 in front below the head very deep, abrupt and subcircular. 

 Intercotylar tuberosity relatively inconspicuous. Tibial facets 

 subequal and with their longest diameters nearly parallel to the 

 sagittal plane. Hypotarsal block set well toward the outer side 

 of the head and with the inner edge much the more prominent. 

 Hypotarsus separate from the head by wide smooth depression, 

 as seen from the proximal end. 



This group, third in the entire series of tarsi, consists of two 

 specimens, a right and a left, taken at the same depth and section 

 cif the excavation. Their identity of characters suggest very 

 strongly their having belonged to the same individual. The 

 specimen from the left side has suffered the loss of the outer 

 trochlea and part of the anteroexternal border of the head. The 

 other specimen lacks the entire head and parts of the three 

 troehleae have been lost by corrosion. The character of the bone 

 is firm with good surface and the foramina of the head are well 

 defined, thus indicating that the bones represent an individual 

 fully mature. 



The species is distinguishable at a glance from the other condors 

 by its extreme slenderness. The total length exceeds that of any of 

 the specimens referred to Gymnogyps calif ornianus but its shaft is 

 actually very much narrower. Unlike the modern condors the shaft 



