i8 



AMPHIBIA AND PISCES OF THE PERMIAN OF NORTH AMERICA 



Revised description: 



1. Horns terminating in a point and curved inward at end. 



posterior edge of skull more sharply concave. 



2. Anterior edge of frontal bone but little anterior to orbits. 



3. Vomerine teeth arranged in a segment of a broad curve. 



4. Anterior end of skull a segment of a broad curve. 



5. Sculpture of facial region distinctly radial from a point 



tween orbits and nares. 



6. Orbits larger. 



The 



be- 



Fig. 2. — Diplocaulus magnicornis. 



Upper view of skull. After Williston. No. 652 Univ. of Chicago. Reduced, pmx, premaxillary; 

 n, nasal; mx, premaxillarj-; ff, prefrontal; /r, frontal; ptf, postfrontal; /, jugal; j?, squamosal; 

 p, parietal; so, supraoccipital plate; psq, prosquamosal; /, tabulare; cl, clavicle; Ic, interclavicle- 

 c, coracoid; h, humerus. 



Diplocaulus magnicornis Cope. 



Cope, Proc. Am. Phil. Soc, vol. xx, 1882, p. 453. 



Phil. Soc, vol. XXXIV, 1896, p. 455. 

 Broili, Paleontographica, Bd. li, 1904, s. 8. 



Also Pal. Bull. 35; Proc. Am. 



Type: A skull and vertebrae. No. 4472 Am. Mus. Nat. Hist. Cope Coll. 

 From Texas. 



Original description, from the first paper by Cope: 



"The skull is very peculiar in the great extent of the parts posterior to 

 the orbits as compared with the portion anterior to them. The posterior 

 border not being complete, the proportions can not be exactly given, but 

 the part anterior to the orbits is two-thirds the length of the part extending 

 from their posterior border to near the base of the lateral horn, and one- 

 fifth the distance from the orbit to the extremity of the horn. The part of 

 the border of the orbit preserved indicates that the latter is of fair size. It 

 is separated from the maxillary border by at least its own diameter. The 

 external nares are peculiarly situated. They are nearer the orbit than the 

 end of the muzzle, and are close to the maxillary border, being separated 

 from the mouth by a narrow strip of bone only. They are round, open 

 nearly laterally, and are removed from the edge of the orbits by the diameter 

 of the latter. 



