The last two cervical vertebrae bear long movable ribs which articulate by distinct capitular and tubercular processes, but do not meet the sternum. The thoracic ribs are eight in number, and each is divisible into a =vertebral= and a =sternal= portion. The first five thoracic ribs are flattened curved bars of bone, which articulate by a prominent =capitulum= with the centrum of the corresponding vertebra, and by a =tuberculum= with the transverse process. Projecting backwards from each is a large hooked =uncinate process.= The last three ribs which are without uncinate processes, become progressively more slender, and in the eighth the tubercular processes are lost. The sternal portions of the ribs are imperfectly ossified pieces, short and comparatively thick in the case of the anterior ribs, longer and more slender in the case of the posterior ribs. THE STERNUM[1]. The =sternum= or breast bone is exceedingly large in the Duck, as in all birds, and projects back far beyond the thorax over much of the anterior part of the abdomen. It is an irregularly oblong plate of bone, abruptly truncated behind, somewhat concave dorsally, and drawn out ventrally into a prominent keel, the =carina=, which projects for some distance forwards beyond the body of the sternum, and tapers off gradually behind. The point where the carina joins the body of the sternum is at the anterior end drawn out into a small process, the =rostrum=[102]. Just dorsolateral to this are a pair of deep grooves, the =coracoid grooves=, with which the coracoids articulate. The sides of the sternum are drawn out in front into a pair of short blunt =costal processes;= and just behind these are a series of seven surfaces with which the ends of the sternal ribs articulate. Immediately behind these surfaces the sides are produced into a pair of long backwardly-projecting =xiphoid processes= which nearly meet processes from the posterior end of the sternum. 2. THE APPENDICULAR SKELETON. This consists of the skeleton of the anterior and posterior limbs and of their respective girdles. A. THE PECTORAL GIRDLE[103]. The pectoral girdle in almost all birds is strongly constructed and firmly united to the sternum. It consists of three bones, a dorsal element, the =scapula=, a posterior ventral element, the =coracoid=, and an anterior ventral element, the _clavicle_.