Page:Notes on Osteology of Baptanodon. With a Description of a New Species.pdf/6

330 with the. These elements are smaller than the parts of B. marshi and B. discus and are hardly more than half the size of B. robustus. They differ in several minor characteristics. The atlas resembles B. marshi and B. robustus in having a single on the lower anterior surface of the. The third and fourth cervicals differ from the same elements of B. marshi in having well developed, and very small.

There is no indication of the parapophysis on the axis as found in both B. marshi and B. discus. Just below the diapophysis and separated from it by a non-articular tract is a faint antero-posterior ridge, which anteriorly probably represents

the rudimentary parapophysis of the atlas. Midway between this ridge and the lower border is a small vertical eminence not observed in the other species. The upper arches of these vertebræ are not sufficiently well preserved to be described here. The other vertebræ preserved appear very similar to the corresponding elements in the other members of this group.

Intervertebral Disks.— Fig. 7 represents the shape and size of the matrix filling the space between the centra of the anterior vertebræ. These disks are quite uniform in character and give an accurate idea of the thickness of the cartilage that once filled the spaces between the centra. The average thickness of the disks at their middle is about 30 mm.

Anterior Limbs.— About half of the proximal portion of one was found. Fig. 8 shows the outline of this articular end. The surface of this