710 E. C. CASE 



are longer in proportion than at either end, rather curved, flattened, and with 

 the shaft little less in width than the extremities. 

 [No 6523.] 



Diplocaulus salamandroides Cope. Plate I, Figs, 16a, 16b, lya, 

 ijb. Plate V, Figs, lya, 17b, 17c, 1yd. 

 Diplocaulus salamandroides Cope, 1877, Proc. Am. Phil. Soc., 



p. 187. (Pal. Bull., No. 26.) 

 Diplocaidus salamandroides Cope, 1882, Proc. Am. Phil. Soc., 



p. 451. (Pal. Bull., No. 35.) 



Cope's generic description is as follows : " Vertebral centra elongate, 

 contracted medially, and perforated by the foramen chorda? dorsalis; coossi- 

 fied with the neural arch, and supporting transverse processes. Two rib 

 articulations one below the other, generally both at the extremities of the 

 processes, but the inferior sometimes sessile. No neural spines nor diapoph- 

 ysis ; the zygapophyses normal and well developed." 



Specific description : " The surface of the centrum is smooth and is with- 

 out grooves. The diapophyses and parapophyses are rather elongate, and are 

 closely approximated one above the other. The superior process issues from 

 the centrum opposite the superior margin of the articular faces. They stand 

 equidistant from the extremities of the centrum, and are directed obliquely 

 backwards. The anterior zygapophyses occupy the same level. The neural 

 spine is a compressed longitudinal ridge ; it divides behind, leaving a notch 

 between the posterior zygapophyses." 



MEASUREMENTS. 



( longitudinal - - .oo6o m 



" Diameter of centrum -I vertical - .0025 



( transverse ... .0025 



Depth of centrum and neural arch - - .0060 



Width with transverse processes - - - .0070 



Expanse of posterior zygapophyses - - .0050 



A portion of a small skull was in contact with one of the vertebra. The 

 ramus of the jaw is shallow and stout, the external surface sculptured with 

 inosculating lines. Teeth with cylindrical roots set in shallow alveoli. The 

 crowns elongate, slightly compressed near the apex, and without grooves or 

 lines. 



In describing the vertebra? of D. magnicomis from Texas (Proc. Am. Phil. 

 Soc, 1882, p. 453) Cope calls attention to the presence of zygospheneandzygan- 

 trum in that species ; they are also present in the D. salamandroides, but are so 

 small as to easily escape notice. The surface of the centrum is stated to be 

 smooth in the Illinois species, this is largely due to weathering, as the more 

 perfect specimens show the same beautiful sculpture as in the Texas forms, 



