514 PROCEEDINGS OF THE ACADEMY OF [1896, 



For specimen No. 14, see list above ; too fragmentary for correct 

 identification. To be named with certainty, No. 15 is also too frag- 

 mentary; while the remarks about specimen No, 15, apply with 

 equal truth to No. 16, though this last has hardly anything beyond 

 the trochlear processes, the distal part of the shaft having been 

 broken off, but a few millimeters above the usual foramen found in 

 this locality. 



Specimen No. 1 7 is a very perfect one, being the left humerus of 

 an adult Partridge, Palceortyx brevipes of Milne-Edwards.* It de- 

 mands no special description. 



In specimen No. 18, we have the fragments of the upper two- 

 thirds of the right tarso-metatarsus, (probably) of some small pas- 

 serine bird, which my meagre material for comparison will not 

 admit of my identifying. On this bone the hypofai'sus is short, be- 

 ing composed of two lateral portions enclosing a tendinal foraminal 

 canal between them. Both of these lateral portions are distinctly 

 grooved in the vertical direction, upon their posterior aspects, by 

 tendinal channels. To identify such a minute, fragmentary speci- 

 men as this, one should have before him for comparison the skele- 

 tons of a representative series of the small birds of France in its 

 existing avifauna, as well as access to such fossil forms as have been 

 discovered or described up to date. To appreciate the difficulty of 

 diagnosis of this nature one has but to make the trial to distinguish 

 the complete skeleton of any one of our American Warblers from 

 those of its near allies in other genera, and my meaning will be 

 made clear. How much more difficult is it then to name, with any 

 hope whatever of being near the truth, the bits of bones of birds of 

 no greater size that existed in a former geologic age of the earth. 

 With skulls, sterna, pelvis and perfect bones all absent this really be- 

 comes impossible — absolutely so in the absence of the material above 

 indicated. 



These remarks apply with equal truth to specimens Nos. 19-23 

 inclusive ; the small pair of carpo-nietacarpi (No. 20) in this series 

 are the smallest fossil bones of this part of the skeleton I have ever 

 seen ; either one of them is as small as the unidentified specimen of 

 this bone in Milne-Edwards' great work, and figured on Plate 155, 

 (Atlas 2, fig. 11) ; they are, however, from a difierent species. 



* See Recherches siir les Oiseaux fossiles de la France, Atlas 2, Plate 130, fig. 

 13. 



