646 S. W. WILLISTON 
separated neuropophyses are vertical and slender, widely separated 
from each other above by the massive spine of the second vertebra. 
Above the middle of each neuropophysis there is a small posterior 
zygapophysis for union with the second vertebra. The hypocentrum 
of the second vertebra is much smaller than the following ones, trans- 
versely oval in shape. There may be pleurocentra here also, but I 
cannot distinguish them. ‘The spine is very massive above, with 
strong rugosities posteriorly, broad from side to side, with the slender 
neuropophyses of the axis lying in contact with it in front. The 
hypocentra of the succeeding vertebrae are almost identical in size and 
shape, scarcely varying a millimeter in length or breadth, though 
those of the sacral region may be a little stouter. Where best pre- 
served they show a flattened surface on the under side separated by a 
ridge from the sides, though in others this flattened part seems to 
be merely a rounded keel. Many of the pleurocentra have been 
dislodged, but such as are in position in different parts of the column 
are alike in shape and in attachment, all rather smaller than the 
anterior or mesial ones of Eryops. The longer neuropophysial 
attachment is with the succeeding arch. ‘These attachments of the 
pleurocentra leave only a small surface on the hypocentrum for union 
with the arch, which, here as in Eryops, for the most part is more 
closely united with the pleurocentrum of the preceding vertebra than 
with that following the arch, to which it presumably belongs. Com- 
plete spines are present in several of the anterior and posterior 
vertebrae, but lack their distal extremities in most of the others. As 
is the case with the hypocentra and pleurocentra they are all nearly 
alike throughout in thickness and length. They are a little com- 
pressed from side to side, and slightly thickened at the upper extremity. 
Anteriorly the spines are nearly vertical, but posteriorly they are 
slightly inclined backward. The transverse processes, springing 
from the arch, are also, so far as can be determined, nearly alike 
throughout the presacral series. They are stout, slightly compressed 
vertically, and are directed nearly straight outward, or a little back- 
ward. The zygapophyses are rather better developed than in 
Eryops, and are not placed so closely together, their articular facets at 
an angle of about forty-five degrees. The transverse process for the 
sacral rib is very stout and heavy, with its large articular facet directed 
