| OCR Text |
Show 328 DE. ST. GEOEGE MIVAET ON THE SKELETON OF [Apr. 2, tuberculum and capitulum not quite so far apart. The posterior articular surface of the centrum is concave. THE SACBUM. This mass of anchylosed vertebrae (figs. 16, 17, 18, & 19) apparently consists in both species of four lumbosacral vertebra, an indeterminable number of sacral vertebrae, and from five to six, probably seven, uro-sacral vertebrae. Fig. 17. 7s °r p vc Lateral aspect of sacrum and pelvis of Psittacus erithacus. ac. Acetabulum. at. Antitrochanteric process. c. Lumbo-sacral vertebra. he. Lateral crest of ilium. Ic. Crest of ilium. If. Iliac fossa. Is. Ilio-caudal spine. of. Obturator foramen. pu. Pubis. r. Sacral ribs. sc. Posterior part of ilium sf. Sacro-sciatic foramen. T H E L U M B O - S A O E A L VEBTEBE-E. These four vertebrae are anchylosed together with the ilium (il), and, of course, with the solid mass of the true sacral vertebrae. The first lumbo-sacral vertebra seen preaxially exhibits its neural arch, prezygapophyses, neural spine, and transverse processes, each presenting a concave tubercular surface, while outside the base of the neural arch just above the centrum is the capitular cup. The preaxial surface of the centrum is concave. |
