262 KANSAS UNIVERSITY SCIENCE BULLETIN. 



can but agree with Hatcher that the tooth figured as Stereo- 

 cephalus resembles the teeth of Paleoscincus. 



The vertebral column is represented by posterior dorsal ver- 

 tebrae, portions of the sacrum and two caudal vertebrae. The 

 remains are more or less fragmentary, but enough is preserved 

 to give a fairly accurate idea of this portion of the animal's 

 anatomy, although it is impossible to determine the vertebral 

 formula. 



The dorsal vertebrse (plate LVIII, figs. 5 and 6) obtained are 

 twelve in number, for the most part imperfectly preserved. 

 They are cylindroid in form, very slightly amphicoelous, nearly 

 amphiplatyan, and the arches are elevated as in Stegosaurus 

 and Polacanthus. The centra are slightly excavated below the 

 base of the neural arch as in Scelidosaurus. The neural canal 

 is small and is wider in the ventral than in the dorsal portion. 

 The centra measure 60 mm. in width by 70 mm. in length. 



The sacrum (plate LIX, figs. 6 and 7) as preserved consists 

 of two sections. One includes three firmly coossified vertebrae 

 of the posterior end and the other a part of the anterior end 

 representing two vertebrae. The anterior section measures 

 120 mm. in length by 70 mm. in width at the widest part. 

 The fragment is very smooth and of a dense bony texture. 

 The neural canal is broad posteriorly but narrows somewhat 

 anteriorly. In plate LIX, figure 2, is represented a cross 

 section through this fragment to show the sacral enlargement 

 at the posterior end. The portion representing the posterior 

 end of the sacrum (plate LIX, figure 7) measures 203 mm. in 

 length by 64 mm. in width at the caudal end. The texture of 

 this part is very fine and compact externally, but internally 

 there is a tendency to a cancellated structure. An interesting 

 characteristic of this element of the skeleton is the high degree 

 of coossification of the various elements composing it. There 

 is not the slightest indication of a suture where the different 

 vertebrae have become joined so that the sacral centra are con- 

 stituted in a solid bony rod tapering somewhat at the anterior 

 end, as do the sacra of Polacanthus (9) and Hylxosauru^ 

 (10). The attachments for the sacral ribs are large, and are 

 placed about midway dorso-ventrally of the centra of the sa- 

 crum. While the sacrum of Stegopelta resembles in a great 

 measure that of Polacanthus, yet it varies from it in that the 

 elements composing it are more highly coossified. This condi- 



