l6 AMPHIBIA AND PISCES OF THE PERMIAN OF NORTH AMERICA 



In the second paper he adds the following characters: 



"Vertebrae with a more or less perfect zygosphen articulation; centra 

 shorter in the anterior than in the median part of the column; axis and 

 atlas solidly united by a long zygosphen, which is not roofed over by the 

 zygantrum. Neural arch continued as a short tube into the foramen mag- 

 num. Atlas unsegmented, and, like the axis, without free hypapophysis. 

 Cervical vertebrae not distinguished from dorsals, and with two-headed 

 ribs. 



" Orbit separated from the maxillary bone by the union of the lachrymal 

 and malar. Either the malar, or more probably the quadratojugal, extends 

 much posterior to the quadrate bone. It is bounded above by the squamo- 

 sal, which extends anteriorly to the distinct post-frontal, thus covering over 

 the temporal fossa. Posteriorly it extends into a long, free process, like the 

 operculum of Polyodon ossified. This horn does not appear to consist of the 

 epiotic, as appears to be the case in Ceraterpeton. The quadrate bone is 

 extended very obliquely forwards and its extremity is divided into an hour- 

 glass-shaped condyle. In other words the condyle consists of two cones 

 with apices continuous. The internal cone is the smaller, and its base is 

 overlapped from before by a flat bone, probably the pterygoid. The cotyli 

 of the mandible correspond. Mandible without angle; symphysis short. 



"The teeth are of about equal size, and are rather slender and with con- 

 ical apex. Their surface is not inflected at any point. The superior series is 

 double, forming two lines between which the mandibular teeth close. This 

 superior series stands near the external edge of the vomer, palatine, and 

 pterygoid bones successively. I have not been able to find any larger teeth 

 in the jaws of this genus. Some fragments, mingled with those here described, 

 display such teeth, but I think they pertain to a species of another genus. 

 I know nothing of the limbs of this genus." 



Revised description: This is contained in the revised description of the 

 family. 



Diplocaulus salamandroides Cope. 



Cope, Proc. Am. Phil. Soc, vol. xvii, 1877, p. 451. 

 Case, Journ. Geol., vol. viii, 1900, p. 710. 



Type: The same as the genus. 



Original 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, leav- 

 ing a notch between the posterior zygapophyses. 



' ' Measurements. 

 "Diameter of the centrum: m 



Longitudinal 0060 



Vertical 0025 



Transverse CX32S 



Depth of centrum and neural arch 0060 



Width of transverse processes 0070 



Expanse of posterior zygapophyses 0050" 



