SYSTEMATIC REVISION OF THE AMPHIBIA. 



AMPHIBIA. 



Order STEGOCEPHALIA. 



Suborder MICROSAURIA (?). 



Family DIPLOCAULID/E Cope. 



Cope, Am. Nat., vol. xv, 1881, p. 164; Proc. Am. Phil. Soc, vol. xx, 1882, p. 452. 

 Broili, Centrlb. f. Min. Geol. u. Pal., 1902, s. 536; Paleontographica, Bd. li, 1904, s. 26. 



Original description: Cope, in his first paper, regarded the Diplocatdidce 

 as belonging in the reptilian group Pelycosauria, but in the second paper he 

 corrected this and gave the following definition: 



"* * * the vertebral centra are not segmented, nor are the inter- 

 centra present in any form. Under this definition it must be referred to the 

 suborder which includes Oestocephalus, Ceraterpeion, etc., for which I have 

 adopted Dawson's name Microsauria. The division includes genera with 

 simple amphicoelous vertebral centra, and teeth without inflection of the 

 dentine." 



Broili's description is, translated: 



" Body long, serpentiform. Centra cylindrical, amphicoelous, zygosphene 

 and zygantrum present. Ribs hollow, two-headed. Teeth conical, smooth, 

 and hollow. Vitrodentin and enamel united and a large pulp cavity present." 



Revised description: Skull enlarged, triangular; prosquamosal, quadrato- 

 jugal, parietal, supraoccipital, and tabulare taking part in the formation of 

 a large horn. Facial region very abbreviate, not over one-fifth the length 

 of the skull. Vertebrae complete, amphicoelous; intercentra absent; diapo- 

 physis and parapophysis separate, attached to middle of vertebra. Zygo- 

 sphene and zygantrum present. Ribs two-headed ; attached intra vertebrally. 

 Teeth conical, without inflected dentine, large pulp cavity present. Clavicle 

 and interclavicle present, large, sculptured on outer surface. Coracoid 

 small, scapula unknown. Limbs present, short and weak. Humerus with 

 entepicondylar foramen. 



Genus DIPLOCAULUS Cope. 



Cope, Proc. Am. Phil. Soc, vol. xvii, 1877, p. 187; also Pal. Bull. No. 26, pub- 

 lished Nov. 20, 1877; Proc. Am. Phil. Soc, vol. xx, 1882, p. 453; also Pal. Bull. 

 No. 35. 



Broili, Centrlb. f. Min. Geol. u. Pal., 1902, 8.536; Paleontographica, Bd.Li, 1904, s. 7. 



Williston, Trans. Kansas Acad. Sci., 1909, p. 122. 



Type: Several vertebrse, Nos. 6513, 6514, 6515, 6516 University of 

 Chicago. From Vermilion County, Illinois, near Danville. 



Original description: In the first paper cited Cope's description is as 

 follows : 



"Vertebral centra elongate, contracted medially, and perforated by the 

 foramen chordae dorsalis ; coossified with the neural arch, and supporting trans- 

 verse 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 diapophysis; the zygapophyses normal and well developed." 



15 



