Biconcave vertebrae, in Ichthyornis, and probably in Archaeopteryx, [6], [49];
perhaps in Enaliornis, [49]
Bill, [11] f.;
arched, [12];
of Balaeniceps and Cancroma, [86];
scissor-like, [12];
wedge-like, [12]
Bill-sheath, [11];
in Chionis, [268];
nature of, [2] n.;