. Bulletin - United States National Museum. Science. 50 BULLETIN 110, UNITED STATES NATIONAL MUSEUM. Whether they increase or decrease in length posteriorly can not be determined from the present specimens, as aU except the one described above lack their distal extremities. The changes that take place in the cervical ribs from first to last are well shown in figure 18. Tlic rib of the sixth cervical was found articulated witli it. The others, though disarticulated, were not far removed from their respective vertebrae in the matrix. The riglit rib of the eightli cervical, which may be considere
. Bulletin - United States National Museum. Science. 50 BULLETIN 110, UNITED STATES NATIONAL MUSEUM. Whether they increase or decrease in length posteriorly can not be determined from the present specimens, as aU except the one described above lack their distal extremities. The changes that take place in the cervical ribs from first to last are well shown in figure 18. Tlic rib of the sixth cervical was found articulated witli it. The others, though disarticulated, were not far removed from their respective vertebrae in the matrix. The riglit rib of the eightli cervical, which may be considered typical of the more posterior cervical ribs, as regards their general shape, is shown in iigure 34. The tuberculum is not lengthened, being braced on the inner side by a thin vertical plate of bone that rises from the top of the short capitular process. Ante- riorly this rib is broad at the base, but narrows rapidly backward. It is tliin throughout; the anterior half, concave above, and convex below. The process extending in front of the tubercuhmi is incomplete, but it was probably roundly pointed. It extends more directly forward and not downward, as in the more anterior ribs. The ^â/ capitulum is short biit exceedingly heavy, with a subcircular, roughened articular obtuse face that fits closely into the deep cup-like parapophysis of the vertebra. When articidated the general direction of the rib is backward and downward with Fig. 34.âCeevical rib of the eight side of the eighth cervical of Antrodemus the head in advance VALENS LEIDT. InNER ASPECT. NO. 4734, J NAT. SIZE. C, ; /â , J . ,;1o t, TUBERCULUM. ^^ "^"^ lUDClClC. The rib of the ninth cervical. No. 8367, (fig. 18), differs principally in its larger size and the more rapid diminution of its posteriorly directed process. Thoracic ribs.âIn Antrodemus there are fourteen ribs in the complete thoracic series on each side. With specimen No. 8367, , there are elev
Size: 2197px × 1137px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorun, bookcentury1800, bookdecade1870, booksubjectscience
