Attached to the upper side of pleurocentrum by a sutural union occurs the neurocentrum. The neural arch is quite large and is oval in outline, although somewhat constricted at the tip. The spine of the neurocentrum is rather long and broad at the base, measuring 12 mm. across the anterior zygapophysis. The neurocentrum is laterally flattened and ends in a rather acute and somewhat rugose point. It was probably tipped with cartilage. The anterior zygapophysis occurs well down on the neurocentrum, its lower edge being 5 mm. from the suture separating the pleurocentrum and the neurocentrum. The posterior zygapophysis occurs quite high up on the neurocentrum and lies at a distance of 15 mm. from the pleuro-neurocentral suture, thus indicating an extreme posterior inclination of the neural spine. The posterior zygapophysis of the best preserved vertebra is separated from its mate, the anterior zygapophysis, in the next succeeding vertebra by a space of 5 mm. The ventral surface of the pleurocentrum bears a structure, which is, without doubt, a chevron, although the character of its opening can not be determined. It is elongated and is united by a broad base to the pleurocentrum. Its union is by a clearly defined suture, which is apparent in 3 vertebræ. The condition represented by the specimen duplicates almost exactly the condition figured by Cope for the caudal region of Cricotus Cope.[D] [Footnote D: COPE, E. D., Trans. Am. Phil. Soc., XVI, p. 246, 1890.] The intercentrum of the present form is fully as large as the pleurocentrum. The significance of this has already been mentioned. The body of the centrum is pierced by a large notochordal canal. Measurements of the Type of Spondylerpeton spinatum Moodie. mm. Length of specimen 60 Length of pleurocentrum 11.5 Height of pleurocentrum to base of neurocentrum 20 Length of neurocentrum 33 Width of neurocentrum at base 9 Width across anterior zygapophysis 12 Width across posterior zygapophysis 10 Length of intercentrum 10 Height of intercentrum 10.5 Height of chevron 3 Length of chevron 18 Width of notochordal opening in centrum 5 Height of same 4.5 Height of neural canal 12 Greatest width of neural canal 6 =Family ERYOPIDÆ Cope, 1882.= Cope, Am. Nat., XVI, p. 334, 1882.