NINTH ANNUAL REPORT. 229 



If we briefly review the various characters of the ratite birds 

 we are as baffled in deciding which is the most speciaHzed, as 

 in studying the meagre fossil remains of this class. Although 

 a bird of strong flight, Ichthyornis yet retained most primitive 

 biconcave vertebrae. In like manner the two-toed, small-winged 

 Ostrich is armed with two good claws on its fingers ; and indeed 

 we find in them all. a similar tangle of old and new characters, 

 as puzzling as they are inspiring to further study. 



