EOCENE BIRDS. 
69 
Deptli of the cup of the same. 0. OOG 
Width of the cup of the same.. 0. 008 
Length of the first caudal.... 0. 020 
Tracsvei’se diameter of the centrum....0. 011 
Length of the eighth caudal. 0. 020 
Diameter of the centrum in front.. 0. 000 
Long diameter of the head of the femur.. 0. 017 
Long diameter of the shaft of the femur... 0. 000 
The condyle of the os qiiadratiim is concave in longitudinal section, and 
the exterior convexity is stouter than the interior. Tlie exterior border has 
a projecting ala as in other specimens. This character is observed in the quad¬ 
rate bone of a second specimen, which agrees in the frontal and vertebral 
bones, &c., with that first described. It is much smaller, a condition due 
to immaturity, as indicated by the free neural arches of the vertebrae. 
I refer here specimens from New Mexico which I formerly called 
C. lieterodon."^ This species was found in corresponding beds in Wyoming, 
and differs from the C. cliamensis in the compressed, trenchant character of 
the premaxillary teeth. 
AYES. 
DIATRYMA, Cope. 
Rroceediugs Academy Pliiladelpliia, 1876, p. 11. 
Whether birds were numerous during the Wahsatch epoeh of the 
Eocene period is not 3 "et ascertained. The accidents to which the remains 
of the Vertebrata of this formation in New Mexico have been subjected 
would be especially destructive to the fragile bones of birds. The expedi¬ 
tion of 1874 obtained only one of the most solid bones of a species of large 
size, which I have referred to a genus distinct from any previously known, 
under the name above given. 
This bone, a tarso-metatarsus, lacks a part of its shaft and the external 
distal condyle. Its proximal end presents a massive hypotarsus, with trun¬ 
cate posterior face, with a single, rather small, ligamentous groove on its 
inner side. The perforating foramina are large, and widely separated on 
both anterior and posterior faces. The inner edge is compressed, and bears 
* System. Cat. Yert. Eoceue New Mexico, U. S. Geog. Survs. W. of lOOth M., 1875, p. 34. 
