"Fig 55. - Actual section of the body in the thoracic region of a bird. N, neural canal; H, haemal canal; c, centrum of a dorsal vertebra; hy, hypapophysis; d, diapophysis; z, zygapophysis; ns, neural spine; r, pleurapophysis, or vertebral part of a free rib, bearing u, uncinate process or epipleura; cr, haemapophyses; or sternal part of the same; st, section of the sternum or breast-bone (haemal spine). Designed by Dr. R. W. Shufeldt, USA. This figure shows such a section, made across the thoracic or chest-region of the trunk. Here the upper ring (neural) is contracted, only surrounding the slender spinal cord, while the lower ring is expanded to enclose the heart and lungs." Elliot Coues, 1884

The Axial Skeleton

"Fig 55. - Actual section of the body in the thoracic region of a bird. N, neural canal; H, haemal canal;…