NEW PERMIAN VERTEBRATES 647 
outward and downward. ‘There is but one true sacral vertebra, 
though the transverse processes of the vertebrae immediately preceding 
or following the sacral are heavier than elsewhere. Altogether the 
vertebrae of Tvematops are very much like those of Eryops, the 
pleurocentra anteriorly somewhat smaller, the transverse processes 
somewhat longer and stouter, and the zygapophyses a little better 
developed. Of the caudals, save the two connected with the sacral 
vertebrae, only one small block of matrix containing several more or 
less confused bones of the distal part of the series is preserved. The 
chevrons are stout and short, united above in a heavy hypocentral 
mass which is excavated in its middle for the notochord. In front 
of one of the preserved chevrons there is a pleurocentrum which 
seems to have separated the hypocentra ventrally. 
The ribs are everywhere short. For the first nine or ten verte- 
brae they are much dilated, both proximally and distally, with the 
distal portion twisted somewhat from the plane of the proximal. 
They have a slight but distinct curvature. In the region of the 
fifteenth vertebrae the ribs are much smaller, with the proximal 
portion less dilated, and with a longer, rounded shaft. The first rib 
preserved in the matrix has its head closely applied to the side of the 
second vertebra. The attachment of the ribs, at least anteriorly, was 
to both the transverse process of the neurocentrum and the pleurocen- 
trum or hypocentrum, though no articular face is visible. The 
sacral rib is quite like that of Eryops. It has a broad, stout, proximal 
portion articulating chiefly with the transverse process, but also below 
and in front with the hypocentrum or region between the hypocentrum 
and pleurocentrum; the distal part is much flattened and expanded, 
and is curved downward. 
Pectoral girdle and extremity.—Scapula-coracoid (Fig. 4). The 
right side of the pectoral girdle was found inclosed in the matrix 
close to the skull, lying on the sides of the anterior vertebrae. 
The preserved parts are very complete. Some fragments of the 
border of the coracoid, and the tip of the clavicle only are missing. 
The united bone, on the whole, resembles that of Eryops, save 
especially in the absence of the cleithrum, which is large and stout 
and closely applied to the front border of the scapula in Eryops. 
The scapula is much expanded above, and is flattened, a little 
