176 MEANING OP THE SYSTEM. 



developed wings (Ichthyornis}. Others (Odontolcce) had teeth em- 



FIG. 119. Archttojiteryx lithogra/phiea. 



bedded in pits, normal vertebra;, no keel to the breast-bone, and 

 rudimentary wings. They were not capable of flight (Hesperornis, 



