286 
AVES. 
AYES. 
Eemains of four species of Birds were found by me in the sands north 
of Pojuaque. One of the species is represented by nearly all of the bones 
of the skeleton of one or both sides, but none of them in an unbroken 
condition. Another possesses the distal extremity of the humerus, proxi¬ 
mal part of the ulna, distal end of radius, and other less characteristic 
pieces. The third is represented by a principal phalange. 
The bones of the second species resemble very much the correspond¬ 
ing parts of the VuUur umhrosus below described. They have from three- 
fifths to two-thirds the linear dimensions of those of that species, and, like 
them, belonged to a rapacious bird. The distal extremity of the humerus 
differs in minor particulars from that of V. umhrosus. Thus the fossae for 
muscular insertions on both the external and internal tuberosities are deeper, 
larger, and more sharply defined, as is also the case with the extensive 
concavity of the external face. The ulnar condyle is more globose. On 
the other hand, the ridges on the superior face of the proximal part of the 
ulna are not so strongly defined as in V. umhrosus., and the projecting lip 
next to the radius has a greater longitudinal extent. The distal end of the 
radius is relatively large, having three-quarters the diameter of that of the 
V. umhrosus. The marginal and middle distal internal tuberosities are less 
unequal in size than in that species. 
The third species is represented by a first phalange. It is shorter and 
stouter than that of V. umhrosus, and was not codssified with the adjacent 
one. Its surface is rather coarsely striate internally and distally, and the 
general form is clumsy. It belonged, perhaps, to a large Gallinaceous bird 
and immature individual. The shaft narrows distally, and the inner side 
has a high, obtuse crest, which is highest near the proximal end. The 
distal end of the shaft is oblique inward. 
Measurements. 
M. 
Length.. 0.024 
Proxiuaal transverse diameter. 0.0085 
Antero posterior diameter at the middle. 0.009 
