44 ROY L. MOODIE 
suture between them is indistinct. They inclose between their pos- 
terior acuminations an interior projection of the squamosal. The 
squamosal has the usual relations and borders the supratemporal 
laterally. The latter element forms the quadrate angle of the 
cranium. 
The entire length of the vertebral column is preserved although 
the nature and structure of its elements cannot be determined. The 
impressions of a few of the vertebrae show that some of the centra 
were amphicoelous but other than this nothing can be stated. The 
cavities which the centra occupied were filled by the white mineral 
matter and the force of the blow which cracked the nodule destroyed 
the form of the mold. It is possible that where the mineral matter 
has filled the cavities the centra were bony or partly so and where the 
cavities were unfilled the centra were entirely cartilaginous. The 
length of the vertebral column from the base of the skull to the last 
impression of a cartilaginous centrum is 33 mm. 
The number of centra between the sacral vertebra and the skull 
is twenty (Fig. 5) as they are preserved but there may have been one 
more, the atlas. Fritsch has represented twenty-one in his restoration ~ 
of Branchiosaurus salamandroides and this is further indication of an 
affinity between the two genera although Credner has represented 
twenty-six presacral vertebrae in Branchiosaurus amblystomus. ‘The 
presacral vertebrae are thus seen to vary within narrow limits, but the 
number of presacrals is near twenty and this may be taken as typical. 
It is interesting to notice that in modern forms of the salamanders the 
presacral vertebrae are about twenty. The significance of this will be 
discussed elsewhere. There is but a single sacral centrum in Mzcrer- 
peton. ‘The sacral rib has not been detected but it is restored after the 
condition given in Branchiosaurus. ‘The right femur partially covers 
the sacral vertebra. Its structure cannot be determined. I count 
impressions of seventeen caudal centra of which at least twelve 
may have been partially ossified. In the cervical region there are 
distinct impressions of transverse processes on at least five vertebrae 
and this number is assigned to the neck although it is by no means 
certain that this is the correct number. The neck was at least short 
if we may judge from the position of the remains of the pectoral 
girdle. No cervical ribs are definitely determined. There is a short 
